U.S. patent application number 12/993721 was filed with the patent office on 2011-03-17 for novel resin composition and use thereof.
This patent application is currently assigned to KANEKA CORPORATION. Invention is credited to Yoshihide Sekito.
Application Number | 20110061915 12/993721 |
Document ID | / |
Family ID | 41398014 |
Filed Date | 2011-03-17 |
United States Patent
Application |
20110061915 |
Kind Code |
A1 |
Sekito; Yoshihide |
March 17, 2011 |
NOVEL RESIN COMPOSITION AND USE THEREOF
Abstract
An object of the present invention is to provide: a (a)
thermosetting resin composition, a photosensitive resin
composition, a resin composition solution, a resin film, and an
insulating film, each of which (i) is curable at a low temperature
(not more than 200.degree. C.), (ii) has excellent flexibility,
electrical insulating reliability, solder heat resistance, and
resistance to organic solvent, (iii) causes less warpage of a
substrate after curing, and (iv) has excellent adhesiveness to a
sealing agent; and a (b) printed wiring board provided with the
insulating film mentioned above. The object of the present
invention is attainable by using a thermosetting resin composition
containing at least a (A) urethane imide oligomer having a terminal
carboxylic acid group and a (B) thermosetting resin.
Inventors: |
Sekito; Yoshihide; (Shiga,
JP) |
Assignee: |
KANEKA CORPORATION
Osaka-shi, Osaka
JP
|
Family ID: |
41398014 |
Appl. No.: |
12/993721 |
Filed: |
May 14, 2009 |
PCT Filed: |
May 14, 2009 |
PCT NO: |
PCT/JP2009/058975 |
371 Date: |
November 19, 2010 |
Current U.S.
Class: |
174/258 ;
522/111; 525/449 |
Current CPC
Class: |
G03F 7/037 20130101;
C08G 73/1035 20130101; H05K 3/287 20130101; C09D 179/08 20130101;
C09D 179/08 20130101; C08G 18/6659 20130101; G03F 7/027 20130101;
C08G 18/44 20130101; H01B 3/306 20130101; C08G 18/348 20130101;
C08G 18/758 20130101; H01B 3/40 20130101; C08L 2666/02
20130101 |
Class at
Publication: |
174/258 ;
525/449; 522/111 |
International
Class: |
H05K 1/00 20060101
H05K001/00; C08L 63/00 20060101 C08L063/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 2, 2008 |
JP |
2008-144983 |
Claims
1. A thermosetting resin composition containing at least: a (A)
urethane imide oligomer having a terminal carboxylic acid group;
and a (B) thermosetting resin.
2. The thermosetting resin composition as set forth in claim 1,
wherein the (A) urethane imide oligomer having a terminal
carboxylic acid group is a tetracarboxylic acid urethane imide
oligomer.
3. The thermosetting resin composition as set forth in claim 1,
wherein: the (A) urethane imide oligomer having a terminal
carboxylic acid group is obtained by (i) reacting at least a (a)
diol compound and a (b) diisocyanate compound so as to synthesize a
terminal isocyanate compound, (ii) reacting the terminal isocyanate
compound with a (c) tetracarboxylic acid dianhydride so as to
synthesize a urethane imide oligomer having a terminal acid
anhydride, and (iii) reacting the urethane imide oligomer having a
terminal acid anhydride with (d) water and/or primary alcohol, the
(a) diol compound being represented by General Formula (1): [Chem.
1] HO R .sub.1OH (1) (wherein R represents a divalent organic
group; and 1 represents an integer of 1 to 20), the (b)
diisocyanate compound being represented by General Formula (2):
[Chem. 2] O.dbd.C.dbd.N--X--N.dbd.C.dbd.O (2) (wherein X represents
a divalent organic group), and the (c) tetracarboxylic acid
dianhydride being represented by General Formula (3): ##STR00016##
(wherein Y represents a tetravalent organic group).
4. The thermosetting resin composition as set forth in claim 3,
wherein the (a) diol compound contains at least a polycarbonate
diol represented by General Formula (4): ##STR00017## wherein each
R.sub.1 independently represents a divalent organic group; and m
represents an integer of 1 to 20.
5. The thermosetting resin composition as set forth in claim 1,
wherein the (A) urethane imide oligomer having a terminal
carboxylic acid group further has a carboxyl group in its side
chain.
6. The thermosetting resin composition as set forth in claim 1,
wherein the (B) thermosetting resin is contained in the
thermosetting resin composition by 1 to 100 parts by weight,
relative to 100 parts by weight of the (A) urethane imide oligomer
having a terminal carboxylic acid group.
7. A photosensitive resin composition containing at least: a
thermosetting resin composition as set forth in claim 1; a (C)
photosensitive resin; and a (D) photopolymerization initiator.
8. The photosensitive resin composition as set forth in claim 7,
wherein: the (A) urethane imide oligomer having a terminal
carboxylic acid group, the (B) thermosetting resin, the (C)
photosensitive resin, and the (D) photopolymerization initiator are
contained in the photosensitive resin composition in such an amount
ratio that the (C) photosensitive resin and the (D)
photopolymerization initiator are contained therein respectively by
10 to 200 parts by weight and by 0.1 to 50 parts by weight,
relative to 100 parts by weight of a total solid content of the (A)
urethane imide oligomer having a terminal carboxylic acid group and
the (B) thermosetting resin.
9. A resin composition solution obtained by dissolving, in an
organic solvent, a thermosetting resin composition as set forth in
claim 1.
10. A resin film obtained by applying, to a surface of a base
material, a resin composition solution as set forth in claim 9 and
then drying the resin composition solution thus applied.
11. An insulating film obtained by curing a resin film as set forth
in claim 10.
12. A printed wiring board provided with an insulating film,
wherein: the insulating film is an insulating film as set forth in
claim 11; and the printed wiring board is covered with the
insulating film.
13. A resin composition solution obtained by dissolving, in an
organic solvent, a photosensitive resin composition as set forth in
claim 7.
14. A resin film obtained by applying, to a surface of a base
material, a resin composition solution as set forth in claim 13 and
then drying the resin composition solution thus applied.
15. An insulating film obtained by curing a resin film as set forth
in claim 14.
16. A printed wiring board provided with an insulating film,
wherein: the insulating film is an insulating film as set forth in
claim 15; and the printed wiring board is covered with the
insulating film.
Description
TECHNICAL FIELD
[0001] The present invention relates to (i) a thermosetting resin
composition which is curable at a low temperature and which can be
preferably used as an insulating material for electric and
electronic purposes, (ii) a photosensitive resin composition which
is curable at a low temperature, which can be preferably used as an
insulating material for electric and electronic purposes, and which
can be developed by an alkaline aqueous solution, (iii) a cured
film and an insulating film obtainable from the thermosetting resin
composition or the photosensitive resin composition, and (iv) a
printed wiring board provided with the insulating film.
BACKGROUND ART
[0002] Polyimide resin has excellent heat resistance, an excellent
electrical insulating property, excellent chemical resistance, and
a mechanical property, and therefore is used for electric and
electronic purposes. For example, the polyimide resin is used as
materials of (i) an isolation film and a protective coating agent
provided on a semiconductor device, (ii) a surface protective
material and a base material resin for a flexible circuit
substrate, an integrated circuit, and the like, and (iii) an
interlayer insulating film and a protective film for a fine
circuit. Particularly, in a case where the polyimide resin is used
as a coating material for wiring lines on a substrate, the
polyimide resin is used in a form of, for example: a cover lay film
that is obtained by applying an adhesive agent on a shaped product
such as a polyimide film; or a liquid cover coat ink made from the
polyimide resin and the like.
[0003] As the polyimide resin solution used as the liquid cover
coat ink, there have been proposed, for example, a polyimide resin
soluble in an organic solvent and a polyimide resin composition
using a thermosetting resin such as epoxy resin (see, for example,
Patent Literatures 1 to 4).
[0004] Further, there has been proposed a curable imide resin
composition in which a low-molecular-weight amide-imide resin
having a carboxyl group and/or a low-molecular-weight imide resin
having a carboxyl group, and an epoxy resin are dissolved (for
example, see Patent Literature 5).
[0005] Further, there has been proposed a curable resin composition
containing an epoxy resin and an imide oligomer having an acid
anhydride group at its terminal, which imide oligomer is obtainable
from an asymmetric aromatic or cycloaliphatic tetracarboxylic acid
dianhydride and diamino polysiloxane (for example, see Patent
Literature 6).
Citation List
[0006] Patent Literature 1
[0007] Japanese Patent Application Publication, Tokukaihei, No.
11-199669 A (1999)
[0008] Patent Literature 2
[0009] Japanese Patent Application Publication, Tokukai, No.
2002-371182 A
[0010] Patent Literature 3
[0011] Japanese Patent Application Publication, Tokukai, No.
2005-220339 A
[0012] Patent Literature 4
[0013] Japanese Patent Application Publication, Tokukai, No.
2006-96825 A
[0014] Patent Literature 5
[0015] Japanese Patent Application Publication, Tokukai, No.
2001-316469 A
[0016] Patent Literature 6
[0017] Japanese Patent Application Publication, Tokukai, No.
2002-97270 A
SUMMARY OF INVENTION
Technical Problem
[0018] However, the polyimide resin composition disclosed in any of
Patent Literatures 1 to 4 is a polymer solution having a high
molecular weight, a high solute molecular weight, and low
solubility in solvent. Therefore, it is difficult to prepare a
solution thereof to have a high solute concentration, and further
it is necessary to volatile a solvent largely to form a coating
film therefrom, for example. This makes it difficult to form the
coating film in a uniform thickness, thereby decreasing
productivity. Further, in a case where the polyimide resin
composition contains a crosslinking agent, only slight reaction of
a polymer having a high molecular weight with the crosslinking
agent in the composition increases the viscosity of an obtainable
solution significantly. Consequently, the resultant polyimide resin
composition solution has poor stability in viscosity and is easily
gelatinized.
[0019] As for the curable imide resin composition, disclosed in
Patent Literature 5, in which composition an epoxy resin and a
low-molecular-weight amide-imide resin having a carboxyl group
and/or a low-molecular-weight imide resin having a carboxyl group
are dissolved, the epoxy resin and a terminal carboxyl group in an
oligomer having no flexible skeleton are reacted with each other.
This causes a cross-link density to be very high and an obtainable
cured film to be hard and fragile. For example, in a case where the
curable imide resin composition is used as an insulating protective
film provided on a flexible base material (for example, a flexible
printed wiring board), which is required to have a flexing
property, the insulating protective film is cracked when the
printed wiring board is bended. Further, in this case, there arises
such a problem that when an applied film of the curable imide resin
composition is cured by heating, the printed wiring board is warped
due to the heating.
[0020] The curable resin composition, disclosed in Patent
Literature 6, which contains an epoxy resin and an imide oligomer
having an acid anhydride group at its terminal, which imide
oligomer is obtained from an asymmetric aromatic or cycloaliphatic
tetracarboxylic acid dianhydride and a diamino polysiloxane, has,
at its terminal, an acid anhydride group that is active at a room
temperature. Therefore, a reaction between the acid anhydride group
and the epoxy resin gradually proceeds, thereby increasing the
viscosity of a solution of the curable resin composition. Thus, the
curable resin composition has poor stability in viscosity. Further,
in a case where a cured film obtained by curing the curable resin
composition is used, for example, as a circuit board material,
impurities contained in the diamino polysiloxane bleed out from the
cured film, thereby causing malfunction of a semiconductor.
Further, the cured film has a surface that is poor in wettability,
which renders its adhesiveness to various sealing agents poor.
[0021] The present invention is accomplished in view of the above
problems. An object of the present invention is to provide: (i) a
thermosetting resin composition, a photosensitive resin
composition, a resin composition solution, a resin film, and an
insulating film, each of which is curable at a low temperature (not
more than 200.degree. C.), has excellent flexibility, electrical
insulating reliability, solder heat resistance, and resistance to
organic solvent, hardly causes a curve of a substrate after being
cured, and has excellent adhesiveness to a sealing agent; and (ii)
a printed wiring board provided with the insulating film.
Solution to Problem
[0022] Inventors of the present invention studied diligently to
achieve the object. As a result of the diligent study, they found a
fact that with the use of a composition containing at least a (A)
urethane imide oligomer having a terminal carboxylic acid group and
a (B) thermosetting resin, it is possible to form a cured film (i)
which is curable at a low temperature (not more than 200.degree.
C.), (ii) which has excellent flexibility, electrical insulating
reliability, solder heat resistance, and resistance to organic
solvent, (iii) which causes less warpage of a substrate after being
cured, and (iv) which has excellent adhesiveness to a sealing
agent. That is, a resin composition solution containing a (A)
urethane imide oligomer having a terminal carboxylic acid group and
a (B) thermosetting resin exhibits low viscosity even though the
solution is prepared to have a high concentration of solute
dissolved therein. In addition, the inventors found that with the
use of the solution, it is possible to form a cured film having
various excellent physical properties. Based on these facts, the
inventors accomplished the present invention. The present invention
can attain the above object by a resin composition having a novel
structure as described below.
[0023] That is, a thermosetting resin composition according to the
present invention contains at least: a (A) urethane imide oligomer
having a terminal carboxylic acid group; and a (B) thermosetting
resin.
[0024] In the thermosetting resin composition according to the
present invention, it is preferable that the (A) urethane imide
oligomer having a terminal carboxylic acid group be a
tetracarboxylic acid urethane imide oligomer.
[0025] Further, in the thermosetting resin composition of the
present invention, it is preferable that the (A) urethane imide
oligomer having a terminal carboxylic acid group be obtained by (i)
reacting at least a (a) diol compound and a (b) diisocyanate
compound so as to synthesize a terminal isocyanate compound, (ii)
reacting the terminal isocyanate compound with a (c)
tetracarboxylic acid dianhydride so as to synthesize a urethane
imide oligomer having a terminal acid anhydride, and (iii) reacting
the urethane imide oligomer having a terminal acid anhydride with
(d) water and/or primary alcohol, the (a) diol compound being
represented by General Formula (1):
[Chem. 1]
HO R .sub.1H (1)
(wherein R represents a divalent organic group; and 1 represents an
integer of 1 to 20), the (b) diisocyanate compound being
represented by General Formula (2):
[Chem. 2]
O.dbd.C.dbd.N--X--N.dbd.C.dbd.O (2)
(wherein X represents a divalent organic group), and the (c)
tetracarboxylic acid dianhydride being represented by General
Formula (3):
##STR00001##
(wherein Y represents a tetravalent organic group).
[0026] Further, in the thermosetting resin composition according to
the present invention, it is preferable that the (a) diol compound
contain at least a polycarbonate diol represented by General
Formula (4):
##STR00002##
wherein each R.sub.1 independently represents a divalent organic
group; and m represents an integer of 1 to 20.
[0027] Moreover, in the thermosetting resin composition according
to the present invention, it is preferable that the (A) urethane
imide oligomer having a terminal carboxylic acid group further have
a carboxyl group in its side chain.
[0028] In the thermosetting resin composition according to the
present invention, it is preferable that the (B) thermosetting
resin be contained in the thermosetting resin composition by 1 to
100 parts by weight, relative to 100 parts by weight of the (A)
urethane imide oligomer having a terminal carboxylic acid
group.
[0029] A photosensitive resin composition according to the present
invention contains at least: any of the aforementioned
thermosetting resin compositions; and a (C) photosensitive resin;
and a (D) photopolymerization initiator.
[0030] In the photosensitive resin composition according to the
present invention, it is preferable that the (A) urethane imide
oligomer having a terminal carboxylic acid group, the (B)
thermosetting resin, the (C) photosensitive resin, and the (D)
photopolymerization initiator be contained in the photosensitive
resin composition in such an amount ratio that the (C)
photosensitive resin and the (D) photopolymerization initiator are
contained therein respectively by 10 to 200 parts by weight and by
0.1 to 50 parts by weight, relative to 100 parts by weight of a
total solid content of the (A) urethane imide oligomer having a
terminal carboxylic acid group and the (B) thermosetting resin.
[0031] A resin composition solution according to the present
invention is obtained by dissolving, in an organic solvent, any of
the aforementioned thermosetting resin composition or any of the
aforementioned photosensitive resin composition.
[0032] A resin film according to the present invention is obtained
by applying, to a surface of a base material, the resin composition
solution and then drying the resin composition solution thus
applied.
[0033] An insulating film according to the present invention is
obtained by curing the resin film.
[0034] A printed wiring board provided with an insulating film,
according to the present invention is arranged such that the
insulating film is the aforementioned insulating film; and the
printed wiring board is covered with the insulating film.
ADVANTAGEOUS EFFECTS OF INVENTION
[0035] As described above, the thermosetting resin composition of
the present invention contains at least a (A) urethane imide
oligomer having a terminal carboxylic acid group and a (B)
thermosetting resin. With the arrangement, when the thermosetting
resin composition is dissolved in an organic solvent, a resultant
thermosetting resin composition solution has a low viscosity
despite having a high concentration of solute dissolved therein.
Further, a cured film obtained from the thermosetting resin
composition of the present invention is excellent in adhesiveness
of a coating film, stability in environmental resistance test,
chemical resistance, flexibility, and wettability of a coating
film, and has excellent physical properties. In view of this, the
thermosetting resin composition of the present invention is
applicable as a protective film or the like provided on various
circuit boards and yields distinguished effects. Further, the
photosensitive resin composition of the present invention using the
thermosetting resin composition is curable at a low temperature
without using siloxane diamine, and exhibits various excellent
properties when it is applied on a wiring board and formed into a
shaped product.
BRIEF DESCRIPTION OF DRAWINGS
[0036] FIG. 1
[0037] FIG. 1 is a schematic view of measuring how much a film is
warped.
DESCRIPTION OF EMBODIMENTS
[0038] The following describes the present invention more
specifically.
[0039] (I) Thermosetting Resin Composition
[0040] A thermosetting resin composition of the present invention
contains at least a (A) urethane imide oligomer having a terminal
carboxylic acid group and a (B) thermosetting resin.
[0041] The (A) urethane imide oligomer having a terminal carboxylic
acid group in the thermosetting resin composition of the present
invention is more preferably a urethane imide oligomer having a
terminal tetracarboxylic acid group, which urethane imide oligomer
is obtainable by use of a polycarbonate diol, but is not limited to
this.
[0042] The inventors of the present invention found that the
thermosetting resin composition of the present invention containing
at least the (A) urethane imide oligomer having a terminal
carboxylic acid group and the (B) thermosetting resin has various
excellent properties. The presumable reason thereof is as
follows.
[0043] That is, since the (A) urethane imide oligomer having a
terminal carboxylic acid group is an oligomer having an imide
skeleton and a urethane bond in a molecular, the (A) urethane imide
oligomer is significantly excellent in solubility in organic
solvent. Besides, in a case where a crosslinking agent is mixed
therewith and a resultant solution is left for stand at a room
temperature, even if the crosslinking agent is slightly reacted
with the oligomer, the solution still maintains a molecular weight
falling within an oligomer range. Accordingly, a thermosetting
resin composition solution having excellent stability in viscosity
at a room temperature can be obtained.
[0044] Further, a cured film containing the (A) urethane imide
oligomer having a terminal carboxylic acid group is excellent in
(i) heat resistance, electrical insulating reliability, and flame
resistance, each derived from the imide skeleton, and (ii) chemical
resistance and flexibility, each derived from the urethane bond.
Particularly, as for the urethane imide oligomer having a terminal
tetracarboxylic acid group, prepared by use of a polycarbonate
diol, a cured film obtained therefrom surprisingly has hydrolysis
resistance derived from a polycarbonate skeleton. Therefore, the
cured film can restrain hydrolysis of the urethane bond at a high
temperature and a high humidity, and thus exhibits excellent
hydrolysis resistance.
[0045] When the carboxyl group contained in the (A) urethane imide
oligomer having a terminal carboxylic acid group is heated, the
carboxyl group is reacted with the (B) thermosetting resin, thereby
causing three-dimensional crosslinking and increasing the molecular
weight of a resultant thermosetting resin composition.
Particularly, in a case where the terminal carboxylic acid is a
tetracarboxylic acid, mixing of the (A) urethane imide oligomer
with the (B) thermosetting resin at a room temperature produces a
thermosetting resin composition solution having a very stable
viscosity, and the reaction between the carboxylic acid and the
thermosetting resin causes no increase in viscosity. This is
because the activity of the tetracarboxylic acid is stabilized to
be low at the room temperature. Note that the reaction between the
(A) urethane imide oligomer having a terminal carboxylic acid group
and the (B) thermosetting resin as the crosslinking agent is
promoted at a temperature of not more than 200.degree. C., more
specifically, around 160 to 170.degree. C. The reason is as
follows: Due to (i) the urethane bond included in the urethane
imide oligomer having a terminal carboxylic acid group, (ii) the
flexibility derived from a diol component as a raw material, and
(iii) high mobility of a molecular skeleton because of a low
molecular weight, molecules actively move even at a curing
temperature of around 160 to 170.degree. C. This causes the
terminal carboxyl group to collide with the crosslinking agent
sufficiently. As a result, the increase in the molecular weight
proceeds while three-dimensional cross-linkage is formed.
[0046] Further, the thermosetting resin composition of the present
invention has no siloxane skeleton in the molecular skeleton.
Therefore, a resultant cured film has a surface having good
wettability and markedly excels in adhesiveness to various members.
Besides, the cured film does not cause bleedout of impurities
derived from a siloxane component. On this account, in a case where
the cured film is used as an insulating film for a printed wiring
board, no malfunction of a semiconductor is induced.
[0047] The following describes the (A) urethane imide oligomer
having a terminal carboxylic acid group, the (B) thermosetting
resin, other components, and a mixture method of (A) and (B), more
specifically.
[0048] <(A) Urethane Imide Oligomer Having Terminal Carboxylic
Acid Group>
[0049] A urethane imide oligomer having a terminal carboxylic acid
group, used in the present invention, is an oligomer (i) which has
at least one carboxylic acid provided at a terminal thereof, (ii)
which has a urethane structure at an inner part thereof, (iii)
whose imide ring is closed, and (iv) whose number-average molecular
weight is not more than 30,000, more preferably not more than
20,000, based on polyethylene glycol.
[0050] More specifically, in the present invention, the (A)
urethane imide oligomer having a terminal carboxylic acid group is
a compound (i) which has no siloxane bond in its main chain
skeleton, (ii) which has at least one repeating unit having a
urethane bond, which repeating unit is represented by General
Formula (5):
##STR00003##
(wherein R and X independently represent a divalent organic group;
and n represents an integer of not less than 1), and (iii) which
has a structure having at least two imide bonds and at least one
carboxyl group at its terminal, which structure is represented by
General Formula (6):
##STR00004##
(wherein each R.sub.2 independently represents a divalent organic
group; each R.sub.3 independently represents a hydrogen atom or an
alkyl group; each Y independently represents a tetravalent organic
group; and p represents an integer of not less than 0).
[0051] Further, the urethane imide oligomer, of the present
invention, having a terminal carboxylic acid group has a
number-average molecular weight of preferably not more than 30,000,
more preferably not more than 20,000, particularly preferably not
more than 15,000, based on polyethylene glycol. It is preferable to
carry out a reaction by controlling the number-average molecular
weight within the above range, because the urethane imide oligomer
having a terminal carboxylic acid group is improved in solubility
in organic solvent.
[0052] Further, the urethane imide oligomer, of the present
invention, having a terminal carboxylic acid group has no siloxane
bond in its structure. Accordingly, a cured film made from the
urethane imide oligomer has a surface that is excellent in
wettability, so that the cured film has excellent adhesiveness to
various sealing agents. Moreover, since the bond in the structure
is not an amide bond but an imide bond, the urethane imide oligomer
having a terminal carboxylic acid group has excellent storage
stability. Therefore, in a case where a resin composition solution
is prepared with the use of the urethane imide oligomer, it is
possible to restrain that the viscosity of the solution changes
over time at the time of storage.
[0053] The (A) urethane imide oligomer having a terminal carboxylic
acid group, which is used in the present invention, is not
particularly limited provided that it has the aforementioned
structure. However, the urethane imide oligomer having a terminal
carboxylic acid group is prepared more preferably by (i) reacting
at least a (a) diol compound represented by General Formula
(1):
[Chem. 7]
HO R .sub.1OH (1)
(wherein R represents a divalent organic group; and 1 represents an
integer of 1 to 20), with a (b) diisocyanate compound represented
by General Formula (2):
[Chem. 8]
O.dbd.C.dbd.N--X--N.dbd.C.dbd.O (2)
(wherein X represents a divalent organic group), so as to
synthesize a terminal isocyanate compound, (ii) reacting the
terminal isocyanate compound with a (c) tetracarboxylic acid
dianhydride represented by General Formula (3):
##STR00005##
(wherein Y represents a tetravalent organic group), so as to
synthesize a urethane imide oligomer having a terminal acid
anhydride, and (iii) reacting the urethane imide oligomer having a
terminal acid anhydride with (d) water and/or primary alcohol.
[0054] <(a) Diol Compound>
[0055] The (a) diol compound used in the present invention is a
branched or straight-chain compound, as represented by General
Formula (1), which has two hydroxyl groups in a molecule. The (a)
diol compound is not particularly limited provided that it has the
above structure. Examples of the diol compound encompass: alkylene
diols such as ethyleneglycol, diethylene glycol, propylene glycol,
1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol,
3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol,
2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol,
1,4-cyclohexanediol, and 1,4-cyclohexanedimethanol; carboxyl
group-containing diols such as dimethylolpropionic acid
(2,2-bis(hydroxymethyl)propionic acid), dimethylol butanoic acid
(2,2-bis (hydroxymethyl)butanoic acid), 2,3-dihydroxybenzoic acid,
2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid,
2,6-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, and
3,5-dihydroxybenzoic acid; polyoxyalkylene diols such as
polyethylene glycol, polypropylene glycol, polytetramethylene
glycol, and a random copolymer of tetramethylene glycol and
neopentyl glycol; a polyester diol obtained by reacting polyhydric
alcohol and polybasic acid; a polycarbonate diol having a carbonate
skeleton; a polycaprolactone diol obtained by carrying out ring
opening addition of lactones such as .gamma.-butyl lactone,
.epsilon.-caprolactone, and .delta.-valerolactone; bisphenol A, an
ethylene oxide adduct of bisphenol A, a propylene oxide adduct of
bisphenol A, hydrogenated bisphenol A, an ethylene oxide adduct of
hydrogenated bisphenol A, a propylene oxide adduct of hydrogenated
bisphenol A, and the like. These compounds can be used solely, or
two or more types thereof can be used in combination.
[0056] It is especially preferable to use, as the (a) diol
compound, a polycarbonate diol represented by General Formula
(4):
##STR00006##
(wherein each R.sub.1 independently represents a divalent organic
group; and m represents an integer of 1 to 20). This is because an
obtainable cured film can be further improved in heat resistance,
flexibility, water resistance, chemical resistance, and electrical
insulating reliability at a high temperature and a high
humidity.
[0057] Specific examples of the polycarbonate diol encompass the
following commercial products: trade names PCDL T-4671, T-4672,
T-4691, T-4692, T-5650J, T-5651, T-5652, T-6001, and T-6002, each
of which is manufactured by Asahi Kasei Chemicals Corporation;
trade names PLACCEL CD CD205, CD205PL, CD205HL, CD210, CD210PL,
CD210HL, CD220, CD220PL, and CD220HL, each of which is manufactured
by Daicel Chemical Industries, Ltd.; trade names Kuraray Polyol
C-1015N, C-1050, C-1065N, C-1090, C-2015N, C-2065N, and C-2090,
each of which is manufactured by Kuraray Co., Ltd.; and trade names
NIPPOLLAN 981, 980R, and 982R, each of which is manufactured by
Nippon Polyurethane Industry Co., Ltd. These products can be used
solely, or two or more types thereof can be used in combination.
The polycarbonate diol has a number-average molecular weight of
preferably 500 to 5,000, more preferably 750 to 2,500, particularly
preferably 1,000 to 2,000, based on polystyrene. When the
number-average molecular weight of the polycarbonate diol is within
the range, an obtainable cured film can be improved in chemical
resistance and flexibility. In a case where the number-average
molecular weight is less than 500, the flexibility of an obtainable
cured film may be decreased in some cases. Further, in a case where
the number-average molecular weight is 5000 or more, the solvent
solubility of the urethane imide oligomer having a terminal
carboxylic acid group may be decreased in some cases.
[0058] Further, it is preferable that the polycarbonate diol and
the carboxyl group-containing diol be used in combination. In this
case, it is possible to introduce a carboxyl group into a side
chain of an obtainable urethane imide oligomer having a terminal
carboxylic acid group. This increases branch points in a main chain
of the urethane imide oligomer having a terminal carboxylic acid
group, thereby decreasing crystallinity. Hence, the solvent
solubility of the urethane imide oligomer having a terminal
carboxylic acid group can be improved.
[0059] <(b) Diisocyanate Compound>
[0060] The (b) diisocyanate compound used in the present invention
is a compound having two isocyanate groups in a molecule, as
represented by General Formula (2).
[0061] Examples of the (b) diisocyanate compound encompass, for
example: aromatic diisocyanate compounds such as
diphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4,2'- or 4,3'-
or 5,2'- or 5,3'- or 6,2'- or 6,3'-dimethyl
diphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4,2'- or 4,3'-
or 5,2'- or 5,3'- or 6,2'- or 6,3'-diethyl
diphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4,2'- or 4,3'-
or 5,2'- or 5,3'- or 6,2'- or 6,3'-dimethoxy
diphenylmethane-2,4'-diisocyanate,
diphenylmethane-4,4'-diisocyanate,
diphenylmethane-3,3'-diisocyanate,
diphenylmethane-3,4'-diisocyanate, diphenylether-4,4'-diisocyanate,
benzophenone-4,4'-diisocyanate, diphenylsulfone-4,4'-diisocyanate,
tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate, m-xylylene
diisocyanate, p-xylylene diisocyanate,
naphthalene-2,6-diisocyanate, and
4,4'-[2,2-bis(4-phenoxyphenyl)propane]diisocyanate; alicyclic
diisocyanate compounds such as hydrogenated diphenylmethane
diisocyanate, hydrogenated xylylene diisocyanate, isophorone
diisocyanate, and norbornene diisocyanate; and aliphatic
diisocyanate compounds such as hexamethylene diisocyanate,
trimethyl hexamethylene diisocyanate, and lysine diisocyanate.
These compounds can be used solely, or two or more types of them
can be used in combination. The use of such a compound is
preferable because a resultant cured film can be improved in heat
resistance. Further, it is also possible to use a compound that is
stabilized with a block agent necessary for avoiding a change over
time. The block agent is not especially limited, and may be, for
example, alcohol, phenol, oxime, or the like.
[0062] The (b) diisocyanate compound is particularly preferably
diphenylmethane-4,4'-diisocyanate,
diphenylmethane-3,3'-diisocyanate,
diphenylmethane-3,4'-diisocyanate, tolylene-2,4-diisocyanate,
tolylene-2,6-diisocyanate, or norbornene diisocyanate. These
compounds are preferable because they can further improve a
resultant cured film in heat resistance and water resistance.
[0063] <Synthesis Method of Terminal Isocyanate Compound>
[0064] A synthesis method used in the present invention for
synthesizing a terminal isocyanate compound by reacting the (a)
diol compound and the (b) diisocyanate compound is such that the
diol compound and the diisocyanate compound are reacted with each
other without solvent or in an organic solvent. In the reaction,
the diol compound and the diisocyanate compound are mixed such that
a ratio of the number of isocyanate groups to the number of
hydroxyl groups (i.e., isocyanate group/hydroxyl group) is not less
than 1 but not more than 2.10, more preferably not less than 1.10
but not more than 2.10, further preferably not less than 1.90 but
not more than 2.10.
[0065] Further, in a case where two or more types of the (a) diol
compound are used, the reaction thereof with the (b) diisocyanate
compound may be carried out after the two or more types of the (a)
diol compound are mixed, or each of the two or more types of the
(a) diol compound may be reacted with the (b) diisocyanate
compound, independently. Alternatively, the reaction may be carried
out such that (i) a (a) diol compound is initially reacted with the
(b) diisocyanate compound, (ii) a resultant terminal isocyanate
compound is reacted with another (a) diol compound, and (iii) a
reactant is further reacted with the (b) diisocyanate compound.
Further, in a case where two or more types of the (b) diisocyanate
compound are used, the reaction can be carried out in the same
manner as above. In this way, an intended terminal isocyanate
compound can be prepared.
[0066] The reaction between (a) and (b) is carried out at a
temperature of, preferably, 40 to 160.degree. C., more preferably
60 to 150.degree. C. If the temperature is less than 40.degree. C.,
it takes too much time for the reaction. If the temperature exceeds
160.degree. C., a three-dimensional reaction occurs during the
reaction, which easily causes gelatinization. How long the reaction
is carried out can be determined appropriately depending on a batch
scale and a reaction condition to be employed. Further, optionally,
the reaction may be carried out in the presence of a catalyst such
as tertiary amines or a metal or semi-metal compound (for example,
alkaline metal, alkaline earth metal, tin, zinc, titanium, or
cobalt).
[0067] The above reaction can be carried out without any solvent.
However, in order to control the reaction, it is preferable to
carry out the reaction by use of an organic solvent. Examples of
the organic solvents encompass: sulfoxide-based solvents such as
dimethyl sulfoxide and diethyl sulfoxide; formamide-based solvents
such as N,N-dimethyl formamide and N,N-diethyl formamide;
acetamide-based solvents such as N,N-dimethylacetamide and
N,N-diethylacetamide; pyrrolidone-based solvents such as
N-methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone; phenol-based
solvents such as phenol, o-, m-, or p-cresol, xylenol, halogenated
phenol, and catechol; hexamethylphosphoramide;
.gamma.-butyrolactone; and the like. Further, these organic
solvents can be used optionally in combination with an aromatic
hydrocarbon such as xylene or toluene, as needed.
[0068] Further examples of the organic solvent that can be used are
solvents of symmetric glycol diethers such as methyl monoglyme
(1,2-dimethoxyethane), methyl diglyme (bis(2-methoxyethyl)ether),
methyl triglyme (1,2-bis(2-methoxyethoxy)ethane), methyl tetraglyme
(bis[2-(2-methoxyethoxyethyl)]ether), ethyl monoglyme
(1,2-diethoxyethane), ethyl diglyme (bis(2-ethoxyethyl)ether), and
butyl diglyme (bis(2-butoxyethyl)ether); solvents of acetates such
as methyl acetate, ethyl acetate, isopropyl acetate, n-propyl
acetate, butyl acetate, propylene glycol monomethyl ether acetate,
ethylene glycol monobutyl ether acetate, diethylene glycol
monoethyl ether acetate (another name: carbitol acetate,
2-(2-butoxyethoxy)ethyl)acetate), diethylene glycol monobutyl ether
acetate, 3-methoxybutyl acetate, ethylene glycol monomethyl ether
acetate, ethylene glycol monoethyl ether acetate, dipropylene
glycol methyl ether acetate, propylene glycol diacetate, and
1,3-butylene glycol diacetate; and solvents of ethers such as
dipropylene glycol methyl ether, tripropylene glycol methyl ether,
propylene glycol n-propyl ether, dipropylene glycol n-propyl ether,
propylene glycol n-butyl ether, dipropylene glycol n-butyl ether,
tripylene glycol n-propyl ether, propylene glycol phenyl ether,
dipropylene glycol dimethyl ether, 1,3-dioxolan, ethylene glycol
monobutyl ether, diethylene glycol monoethyl ether, diethylene
glycol monobutyl ether, and ethylene glycol monoethyl ether. Among
these solvents, it is preferable to use the symmetric glycol
dieters, because the symmetric glycol dieters hardly cause side
reaction.
[0069] It is desirable that the solvent used in the reaction be
added so that a solute weight concentration in a reaction solution,
i.e., a concentration of the reaction solution is not less than 5%
by weight but not more than 90% by weight. The solute weight
concentration in the reaction solution is more desirably not less
than 10% by weight but not more than 80% by weight. In a case where
the concentration of the reaction solution is 5% by weight or less,
it is difficult to cause a polymerization reaction and a reaction
speed decreases. This may result in that an intended structural
substance cannot be prepared. For this reason, the concentration of
5% by weight or less is not preferable.
[0070] Further, as for the terminal isocyanate compound obtained as
a result of the reaction, an isocyanate group provided at a resin
terminal can be blocked with a blocking agent such as alcohols,
lactums, or oximes, after the synthesis is completed.
[0071] <Synthesis Method of Urethane Imide Oligomer Having
Terminal Acid Anhydride>
[0072] The urethane imide oligomer having a terminal acid
anhydride, used in the present invention, can be prepared by
reacting the terminal isocyanate compound synthesized in the
aforementioned manner, with a tetracarboxylic acid dianhydride. The
terminal isocyanate compound and the tetracarboxylic acid
dianhydride are mixed such that a ratio of the number of acid
dianhydride groups to the number of isocyanate groups (i.e., acid
dianhydride group/isocyanate group) is preferably not more than
2.10, more preferably not less than 1.10 but not more than 2.10,
further preferably not less than 1.90 but not more than 2.10. The
reaction between the terminal isocyanate compound and the
tetracarboxylic acid dianhydride may be carried out with the use of
the solvent that is used for synthesis of the terminal isocyanate
compound. Optionally, a solvent as exemplified above may be further
added.
[0073] <Tetracarboxylic Acid Dianhydride>
[0074] As the tetracarboxylic acid dianhydride for use in
synthesizing the urethane imide oligomer having a terminal acid
anhydride in the present invention, it is possible to use
tetracarboxylic acid dianhydrides such as 3,3',4,4'-benzophenone
tetracarboxylic acid dianhydride, pyromellitic acid dianhydride,
3,3',4,4'-oxydiphthalic acid dianhydride,
2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, 2,2-bis
(4-hydroxyphenyl)propane dibenzoate-3,3',4,4'-tetracarboxylic acid
dianhydride, 3,3',4,4'-diphenyl sulfone tetracarboxylic acid
dianhydride, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride,
2,3,3',4-biphenyltetracarboxylic acid dianhydride, and
5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic
acid anhydride.
[0075] The tetracarboxylic acid dianhydride for use in synthesizing
the urethane imide oligomer having a terminal acid anhydride is
more preferably 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane
dianhydride, 3,3',4,4'-diphenyl sulfone tetracarboxylic acid
dianhydride, 3,3',4,4'-oxydiphthalic acid dianhydride. With the use
of such a tetracarboxylic acid dianhydride, it is possible to
improve (i) an obtainable urethane imide oligomer having a terminal
carboxylic acid group in terms of solubility in organic solvent and
(ii) an obtainable cured film in terms of chemical resistance.
[0076] Further, the tetracarboxylic acid dianhydride is further
preferably 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane
dianhydride or
5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic
acid anhydride, from the viewpoint of compatibility to other
materials contained in a thermosetting resin composition to be
prepared.
[0077] The tetracarboxylic acid dianhydride used in the present
invention is added preferably by not less than 1.50 mol but not
more than 2.50 mol relative to 1 mol of polyol (more specifically,
a diol compound) used for preparing the terminal isocyanate
compound, from the viewpoint of preparing the urethane imide
oligomer having a terminal carboxylic acid group so as to have a
carboxyl group at each terminal thereof. The tetracarboxylic acid
dianhydride is added particularly preferably by not less than 1.90
mol but not more than 2.10 mol. When the tetracarboxylic acid
dianhydride is added in the above range, it is possible to reduce
an amount of the tetracarboxylic acid dianhydride that does not
contribute to the reaction.
[0078] <Method for Producing Urethane Imide Oligomer Having
Terminal Acid Anhydride>
[0079] In producing the urethane imide oligomer having a terminal
acid anhydride, various methods can be used as a method for
reacting the terminal isocyanate compound and the tetracarboxylic
acid dianhydride. The following describes typical methods, but any
method can be used as long as a tetracarboxylic acid dianhydride
can be provided at a terminal of the urethane imide oligomer.
[0080] Method 1: A tetracarboxylic acid dianhydride is dispersed or
dissolved in an organic solvent, and then a terminal isocyanate
compound is gradually added therein. A reaction temperature at this
time is not less than 100.degree. C. but not more than 300.degree.
C., more preferably not less than 140.degree. C. but not more than
250.degree. C. It is preferable that the reaction occur at the same
time as addition of the terminal isocyanate compound during heating
at such a temperature, so as to promote imidization. Such a method
can be also employed that a terminal isocyanate compound and a
tetracarboxylic acid dianhydride are completely dissolved at a low
temperature, and a resultant mixture is heated to a high
temperature so that the resultant mixture is imidized.
[0081] Method 2: A tetracarboxylic acid dianhydride is dispersed or
dissolved in an organic solvent, and a terminal isocyanate compound
is gradually added in a resultant mixture and dissolved therein. An
obtained solution that is evenly dissolved is heated and dried in a
vacuum pressure drier heated at not less than 100.degree. C. but
not more than 250.degree. C., while air is evacuated, thereby
carrying out imidization.
[0082] <Synthesis of Urethane Imide Oligomer Having Terminal
Carboxylic Acid Group>
[0083] A urethane imide oligomer having a terminal carboxylic acid
group is obtainable by reacting the urethane imide oligomer having
a terminal acid anhydride thus prepared in the above method, with
water and/or primary alcohol. The primary alcohol is not limited
particularly. For example, methanol, ethanol, propanol, butanol, or
the like can be used preferably.
[0084] The urethane imide oligomer having a terminal acid anhydride
is reacted with water and/or primary alcohol in such a manner that
the water and/or primary alcohol is added to the urethane imide
oligomer having a terminal acid anhydride in a proportion of
preferably not less than 2.0 times but not more than 300 times,
further preferably not less than 2.0 time but not more than 200
times as large as a molar quantity of the tetracarboxylic acid
dianhydride used for preparing the urethane imide oligomer having a
terminal acid anhydride, so as to open a ring. The reaction can be
carried out without any solvent. However, it is also possible to
carry out the reaction with the use of the following solvents, for
example: sulfoxide-based solvents such as dimethyl sulfoxide and
diethyl sulfoxide; formamide-based solvents such as N,N-dimethyl
formamide and N,N-diethyl formamide; acetamide-based solvents such
as N,N-dimethylacetamide and N,N-diethylacetamide;
pyrrolidone-based solvents such as N-methyl-2-pyrrolidone and
N-vinyl-2-pyrrolidone; phenol-based solvents such as phenol, o-,
m-, or p-cresol, xylenol, halogenated phenol, and catechol;
solvents of symmetric glycol diethers such as
hexamethylphosphoramide, .gamma.-butyrolactone, methyl monoglyme
(1,2-dimethoxyethane), methyl diglyme (bis(2-methoxyethyl)ether),
methyl triglyme (1,2-bis(2-methoxyethoxy)ethane), methyl tetraglyme
(bis[2-(2-methoxyethoxyethyl)]ether), ethyl monoglyme
(1,2-diethoxyethane), ethyl diglyme (bis(2-ethoxyethyl)ether), and
butyl diglyme (bis(2-butoxyethyl)ether); solvents of acetates such
as .gamma.-butyrolactone, N-methyl-2-pyrrolidone, methyl acetate,
ethyl acetate, isopropyl acetate, n-propyl acetate, butyl acetate,
propylene glycol monomethyl ether acetate, ethylene glycol
monobutyl ether acetate, diethylene glycol monoethyl ether acetate
(another name: carbitol acetate, 2-(2-butoxyethoxy)ethyl)acetate),
diethylene glycol monobutyl ether acetate, 3-methoxybutyl acetate,
ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl
ether acetate, dipropylene glycol methyl ether acetate, propylene
glycol diacetate, and 1,3-butylene glycol diacetate; and solvents
of ethers such as dipropylene glycol methyl ether, tripropylene
glycol methyl ether, propylene glycol n-propyl ether, dipropylene
glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene
glycol n-butyl ether, tripylene glycol n-propyl ether, propylene
glycol phenyl ether, dipropylene glycol dimethyl ether,
1,3-dioxolan, ethylene glycol monobutyl ether, diethylene glycol
monoethyl ether, diethylene glycol monobutyl ether, and ethylene
glycol monoethyl ether. Note that hexane, acetone, toluene, xylene
or the like, each of which has a low boiling point, may be used in
combination if necessary. Among these solvents, the solvents of the
symmetric glycol dieters are particularly preferable because the
oligomer is highly soluble therein.
[0085] The reaction is preferably carried out by heating in such a
range that the water and/or primary alcohol thus added does not go
beyond a reaction system. The heating is carried out at a
temperature of not less than 20.degree. C. but not more than
150.degree. C., more preferably not more than 120.degree. C. The
temperature in the above range is preferable because the reaction
is easily promoted. It is preferable to add a more amount of the
water and/or primary alcohol. However, if the water and/or primary
alcohol is added too much, solubility of other additive resins
decreases. On this account, it is preferable to remove an unreacted
residue after the reaction. The unreacted residue is removed at a
temperature equal to or higher than a boiling point of the added
water and/or primary alcohol. The heating at such a temperature can
remove the unreacted residue out of the reaction system.
[0086] <(B) Thermosetting Resin>
[0087] The (B) thermosetting resin in the present invention is a
compound that generates a crosslinked structure by heating, and
serves as a crosslinking agent. Examples of the thermosetting resin
encompass: thermosetting resins such as amino resin, melamine
resin, guanamine resin, urea resin, sulfonamide resin, aniline
resin, cyanate ester resin, isocyanate resin, epoxy resin, phenoxy
resin, phenol resin, xylene resin, furan resin, oxetane resin,
bismaleimide resin, bisallylnadiimide resin, benzoxazine, oxazoline
resin, acrylic resin, methacrylic resin, curable hydrosilyl resin,
curable allyl resin, alkyd resin, and unsaturated polyester resin;
and side-chain reactive group type thermosetting polymers having a
reactive group, such as an allyl group, a vinyl group, an
alkoxysilyl group, a hydrosilyl group, an acryloyl group, or a
methacryloyl group, on a side chain or a terminal of its polymer
chain. Such thermosetting components, i.e., the (B) thermosetting
resin can be used solely, or two or more types thereof can be used
in combination.
[0088] Among these resins, it is more preferable to use the epoxy
resin as the (B) thermosetting resin. If the thermosetting resin
composition contains an epoxy resin component, not only heat
resistance but also adhesiveness to a conductor (e.g., a metal
foil) and a circuit board can be imparted to a cured resin obtained
by curing the thermosetting resin composition.
[0089] The epoxy resin is a compound having at least two epoxy
groups in a molecule. Examples of the epoxy resin encompass:
bisphenol A type epoxy resins, such as trade names jER 828, jER
1001, and jER 1002, each manufactured by Japan Epoxy Resins Co.,
Ltd., trade names ADEKA RESIN EP-4100E and ADEKA RESIN EP-4300E
manufactured by ADEKA Corporation, trade names RE-310S and RE-410S
manufactured by Nippon Kayaku Co., Ltd., trade names EPICLON 840S,
EPICLON 850S, EPICLON 1050, and EPICLON 7050, each manufactured by
Dainippon Ink and Chemicals Inc., and trade names EPOTOHTO YD-115,
EPOTOHTO YD-127, and EPOTOHTO YD-128, each manufactured by Tohto
Kasei Co., Ltd.; bisphenol F type epoxy resins, such as trade names
jER 806 and jER 807 manufactured by Japan Epoxy Resins Co., Ltd.,
ADEKA RESIN EP-4901E, ADEKA RESIN EP-4930, and ADEKA RESIN EP-4950,
each manufactured by ADEKA Corporation, trade names RE-3035,
RE-3045, RE-4035, and RE-4045, each manufactured by Nippon Kayaku
Co., Ltd., trade names EPICLON 830 and EPICLON 835 manufactured by
Dainippon Ink and Chemicals Inc., and trade names EPOTOHTO YDF-170,
EPOTOHTO YDF-1755, and EPOTOHTO YDF-2001, each manufactured by
Tohto Kasei Co., Ltd.; bisphenol S type epoxy resins, such as trade
name EPICLON EXA-1514 manufactured by Dainippon Ink and Chemicals
Inc.; hydrogenated bisphenol A type epoxy resins, such as trade
names jERYX 8000, jERYX 8034, and jERYL 7170, each manufactured by
Japan Epoxy Resins Co., Ltd., trade name ADEKA RESIN EP-4080E
manufactured by ADEKA Corporation, trade name EPICLON EXA-7015
manufactured by Dainippon Ink and Chemicals Inc., and trade names
EPOTOHTO YD-3000 and EPOTOHTO YD-4000D manufactured by Tohto Kasei
Co., Ltd.; biphenyl type epoxy resins, such as trade names jERYX
4000, jERYL 6121H, jERYL 6640, and jERYL 6677, each manufactured by
Japan Epoxy Resins Co., Ltd., and trade names NC-3000 and NC-3000H
manufactured by Nippon Kayaku Co., Ltd.; phenoxy type epoxy resins,
such as trade names jER 1256, jER 4250, and jER 4275, each
manufactured by Japan Epoxy Resins Co., Ltd.; naphthalene type
epoxy resins, such as trade names EPICLON HP-4032, EPICLON HP-4700,
and EPICLON HP-4200, each manufactured by Dainippon Ink and
Chemicals Inc., and trade name NC-7000L manufactured by Nippon
Kayaku Co., Ltd.; phenol novolac type epoxy resins, such as trade
names jER 152 and jER 154 manufactured by Japan Epoxy Resins Co.,
Ltd., trade name EPPN-201-L manufactured by Nippon Kayaku Co.,
Ltd., trade names EPICLON N-740 and EPICLON N-770 manufactured by
Dainippon Ink and Chemicals Inc., and trade name EPOTOHTO YDPN-638
manufactured by Tohto Kasei Co., Ltd.; cresol novolac type epoxy
resins, such as trade names EOCN-1020, EOCN-102S, EOCN-103S, and
EOCN-104S, each manufactured by Nippon Kayaku Co., Ltd., and trade
names EPICLON N-660, EPICLON N-670, EPICLON N-680, and EPICLON
N-695, each manufactured by Dainippon Ink and Chemicals Inc.;
trisphenolmethane type epoxy resins, such as trade names EPPN-501H,
EPPN-501HY, and EPPN-502H, each manufactured by Nippon Kayaku Co.,
Ltd.; dicyclopentadiene type epoxy resins, such as trade name
XD-1000 manufactured by Nippon Kayaku Co., Ltd. and trade name
EPICLON HP-7200 manufactured by Dainippon Ink and Chemicals Inc.;
amine type epoxy resins, such as trade names EPOTOHTO YH-434 and
EPOTOHTO YH-434L manufactured by Tohto Kasei Co., Ltd.; flexible
epoxy resins, such as trade names jER 871, jER 872, jERYL 7175, and
jERYL 7217, each manufactured by Japan Epoxy Resins Co., Ltd., and
trade name EPICLON EXA-4850 manufactured by Dainippon Ink and
Chemicals Inc.; urethane-denatured epoxy resins, such as trade
names ADEKA RESIN EPU-6, ADEKA RESIN EPU-73, and ADEKA RESIN
EPU-78-11, each manufactured by ADEKA Corporation; rubber-denatured
epoxy resins, such as trade names ADEKA RESIN EPR-4023, ADEKA RESIN
EPR-4026, and ADEKA RESIN EPR-1309, each manufactured by ADEKA
Corporation; and chelate-denatured epoxy resins, such as trade
names ADEKA RESIN EP-49-10 and ADEKA RESIN E P-49-20 manufactured
by ADEKA Corporation.
[0090] Further, in the thermosetting resin composition of the
present invention, a curing agent for curing the thermosetting
compound may be added. The curing agent is not particularly
limited, but may be, for example: a phenolic resin such as phenol
novolac resin, cresol novolac resin, or naphthalene type phenolic
resin; melamine; dicyandiamide, or the like. Such a curing agent
can be used solely, or two or more types of the curing agent can be
used in combination.
[0091] Moreover, a curing accelerator for the thermosetting
compound is not especially limited. Examples of the curing
accelerator encompass: phosphine-based compounds such as
triphenylphosphine; amine-based compounds such as tertiary amine,
trimethanolamine, triethanolamine, and tetraethanolamine;
borate-based compounds such as
1,8-diaza-bicyclo[5,4,0]-7-undecenium tetraphenylborate; imidazoles
such as imidazole, 2-ethyl imidazole, 2-ethyl-4-methyl imidazole,
2-phenyl imidazole, 2-undecyl imidazole, 1-benzyl-2-methyl
imidazole, 2-heptadecylimidazole, 2-isopropyl imidazole,
2,4-dimethyl imidazole, and 2-phenyl-4-methyl imidazole;
imidazolines such as 2-methyl imidazoline, 2-ethyl imidazoline,
2-isopropyl imidazoline, 2-phenyl imidazoline,
2-undecylimidazoline, 2,4-dimethyl imidazoline, and
2-phenyl-4-methyl imidazoline; azine-based imidazoles such as
2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine,
2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, and
2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine.
These curing accelerators can be used solely, or two or more types
thereof can be used in combination.
[0092] The component (B) is contained in the thermosetting resin
composition of the present invention by preferably 1 to 100 parts
by weight, more preferably 1 to 50 parts by weight, particularly
preferably 5 to 50 parts by weight, relative to 100 parts by weight
of the component (A).
[0093] By adjusting the amount of the component (B) in the above
range, it is possible to improve a cured film obtainable by curing
the thermosetting resin composition in heat resistance, chemical
resistance, and electrical insulating reliability. Thus, the above
range of the amount of the component (B) is preferable.
[0094] If the amount of the component (B) is less than the above
range, a cured film obtainable by curing the thermosetting resin
composition may have poor heat resistance and electrical insulating
reliability. Further, if the amount of the component (B) is more
than the above range, the cured film obtainable by curing the
thermosetting resin composition is fragile and has poor
flexibility, thereby causing the cured film to be warped
largely.
[0095] (II) Photosensitive Resin Composition
[0096] A photosensitive resin composition of the present invention
may contain at least the thermosetting resin composition, a (C)
photosensitive resin, and a (D) photopolymerization initiator. As
long as the thermosetting resin composition to be used for the
photosensitive resin composition of the present invention is the
aforementioned thermosetting resin composition, any thermosetting
resin composition can be used without any particularly
limitation.
[0097] That is, the photosensitive resin composition of the present
invention may contain at least a (A) urethane imide oligomer having
a terminal carboxylic acid group, a (B) thermosetting resin, a (C)
photosensitive resin, and a (D) photopolymerization initiator.
[0098] Note that, in the photosensitive resin composition, as the
(A) urethane imide oligomer having a terminal carboxylic acid
group, it is more preferable to use a urethane imide oligomer
having a terminal tetracarboxylic acid group which urethane imide
oligomer is obtainable by use of a polycarbonate diol. However, the
(A) urethane imide oligomer is not limited to this.
[0099] The inventors of the present invention found that a
photosensitive resin composition of the present invention, which
contains at least a (A) urethane imide oligomer having a terminal
carboxylic acid group. a (B) thermosetting resin, a (C)
photosensitive resin, and a (D) photopolymerization initiator, has
various excellent properties. The inventors assume that the reasons
thereof are as follows:
[0100] That is, the (A) urethane imide oligomer having a terminal
carboxylic acid group has an imide skeleton and a urethane bond in
a molecule. Therefore, the (A) urethane imide oligomer is excellent
in (i) heat resistance and electrical insulating reliability, which
are derived from the imide skeleton, and (ii) chemical resistance
and flexibility, which are derived from the urethane bond.
Moreover, since the (A) urethane imide oligomer has a carboxyl
group at its terminal, the (A) urethane imide oligomer is soluble
in a developing solution, as typified by a dilute alkaline aqueous
solution. This allows an obtainable photosensitive resin
composition to be finely processed by exposure and development.
Especially, the urethane imide oligomer having a terminal
tetracarboxylic acid group which urethane imide oligomer is
obtained by use of a polycarbonate diol has excellent chemical
resistance derived from its polycarbonate skeleton, thereby causing
the following surprising effects. That is, even though the urethane
imide oligomer has many carboxyl groups at its terminal, an exposed
portion (cured portion) of an obtainable coating film is not
damaged by a developing solution at all (that is, no swelling,
dissolving, or the like of the coating film occurs). On the other
hand, since the urethane imide oligomer has many carboxyl groups at
its terminal as such, an unexposed portion (uncured portion) in the
coating film is dissolved at short developing times. As a result,
it is possible to obtain a pattern having very excellent
resolution.
[0101] Since the components (A) and (B) have been already described
in the foregoing (I), further explanations thereof are omitted. The
following deals with the (C) photosensitive resin, the (D)
photopolymerization initiator, other components, and how to mix the
components (A) to (D).
[0102] <(C) Photosensitive Resin>
[0103] In the present invention, the (C) photosensitive resin is a
resin in which a chemical bond is formed by a photopolymerization
initiator. The photosensitive resin is preferably a resin having at
least one unsaturated double bond in a molecule. Moreover, the
unsaturated double bond is preferably an acrylic group
(CH.sub.2.dbd.CH-- group), a methacryloyl group
(CH.dbd.C(CH.sub.3)-- group), or a vinyl group (--CH.dbd.CH--
group).
[0104] Preferable examples of the (C) photosensitive resin
encompass, for example: bisphenol F EO-denatured (n=2 to 50)
diacrylate, bisphenol A EO-denatured (n=2 to 50) diacrylate,
bisphenol S EO-denatured (n=2 to 50) diacrylate, bisphenol F
EO-denatured (n=2 to 50) dimethacrylate, bisphenol A EO-denatured
(n=2 to 50) dimethacrylate, bisphenol S EO-denatured (n=2 to 50)
dimethacrylate, 1,6-hexanediol diacrylate, neopentyl glycol
diacrylate, ethylene glycol diacrylate, pentaerythritol diacrylate,
trimethylolpropane triacrylate, pentaerythritol triacrylate,
dipentaerythritol hexaacyrlate, tetramethylolpropane tetraacrylate,
tetraethylene glycol diacrylate, 1,6-hexanediol dimethacrylate,
neopentyl glycol dimethacrylate, ethylene glycol dimethacrylate,
pentaerythritol dimethacrylate, trimethylolpropane trimethacrylate,
pentaerythritol trimethacrylate, dipentaerythritol
hexamethacrylate, tetramethylolpropane tetramethacrylate,
tetraethylene glycol dimethacrylate, methoxy diethylene glycol
methacrylate, methoxy polyethylene glycol methacrylate,
.beta.-methacryloyloxyethyl hydrogen phthalate,
.beta.-methacryloyloxyethyl hydrogen succinate,
3-chloro-2-hydroxypropyl methacrylate, stearyl methacrylate,
phenoxyethyl acrylate, phenoxydiethylene glycol acrylate,
phenoxypolyethylene glycol acrylate, .beta.-acryloyloxyethyl
hydrogen succinate, lauryl acrylate, ethylene glycol
dimethacrylate, diethylene glycol dimethacrylate, triethylene
glycol dimethacrylate, polyethylene glycol dimethacrylate,
1,3-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate,
neopentyl glycol dimethacrylate, polypropylene glycol
dimethacrylate, 2-hydroxy-1,3-dimethacryloxypropane,
2,2-bis[4-(methacryloxyethoxy)phenyl]propane,
2,2-bis[4-(methacryloxy diethoxy)phenyl]propane,
2,2-bis[4-(methacryloxy polyethoxy)phenyl]propane, polyethylene
glycol diacrylate, tripropylene glycol diacrylate, polypropylene
glycol diacrylate, 2,2-bis[4-(acryloxy diethoxy)phenyl]propane,
2,2-bis[4-(acryloxy polyethoxy)phenyl]propane,
2-hydroxy-1-acryloxy-3-methacryloxypropane, trimethylolpropane
trimethacrylate, tetramethylolmethane triacrylate,
tetramethylolmethane tetraacrylate, methoxydipropylene glycol
methacrylate, methoxytriethylene glycol acrylate,
nonylphenoxypolyethylene glycol acrylate, nonylphenoxypolypropylene
glycol acrylate, 1-acryloyloxypropyl-2-phthalate, isostearyl
acrylate, polyoxyethylenealkyl ether acrylate, nonylphenoxyethylene
glycol acrylate, polypropylene glycol dimethacrylate,
1,4-butanediol dimethacrylate, 3-methyl-1,5-pentanediol
dimethacrylate, 1,6-mexanediol dimethacrylate, 1,9-nonanediol
methacrylate, 2,4-diethyl-1,5-pentanediol dimethacrylate,
1,4-cyclohexane dimethanol dimethacrylate, dipropylene glycol
diacrylate, tricyclodecane dimethanol diacrylate, 2,2-hydrogenated
bis[4-(acryloxy polyethoxy)phenyl]propane, 2,2-bis[4-(acryloxy
polypropoxy)phenyl]propane, 2,4-diethyl-1,5-pentanediol diacrylate,
ethoxylated trimethylolpropane triacrylate, propoxylated
trimethylolpropane triacrylate, isocyanuric acid tri(ethane
acrylate), pentaerythritol tetraacrylate, ethoxylated
pentaerythritol tetraacrylate, propoxylated pentaerythritol
tetraacrylate, ditrimethylolpropane tetraacrylate,
dipentaerythritol polyacrylate, triallyl isocyanurate, glycidyl
methacrylate, glycidyl allyl ether,
1,3,5-triacryloylhexahydro-s-triazine, triallyl
1,3-5-benzenecarboxylate, triallylamine, triallyl citrate, triallyl
phosphate, allobarbital, diallylamine, diallyl dimethyl silane,
diallyl disulfide, diallyl ether, diallyl cyanurate, diallyl
isophthalate, diallyl terephthalate, 1,3-diallyloxy-2-propanol,
diallyl sulfide diallyl maleate, 4,4'-isopropylidene diphenol
dimethacrylate, 4,4'-isopropylidene diphenol diacrylate, and the
like. However, the (C) photosensitive resin preferably is not
limited to the above examples. Especially, a diacrylate or
methacrylate having 2 to 50 repeating units of EO (ethylene oxide)
per molecule is preferable, and a diacrylate or methacrylate having
2 to 40 repeating units of EO per molecule is more preferable. When
the diacrylate or methacrylate having 2 to 50 repeating units of EO
is used, solubility of the photosensitive resin composition in an
aqueous developing solution, which is typically represented by an
alkaline aqueous solution, is improved, and the developing time is
reduced. In addition to that, stress does not easily remain in a
cured film prepared by curing the photosensitive resin composition.
For example, when the photosensitive resin composition is laminated
on a flexible printed wiring board (as one example of printed
wiring boards) which includes a polyimide resin as a base material,
curling of the printed wiring board can be restrained.
[0105] It is especially preferable to use the EO-denatured
diacrylate or a dimethacrylate, and an acrylic resin having at
least three acrylic groups or methacrylic groups in combination, in
view of improving developing properties. Examples of the acrylic
resin that is suitably used encompass ethoxylated isocyanuric acid
EO-denatured triacrylate, ethoxylated isocyanuric acid EO-denatured
trimethacrylate, ethoxylated trimethylolpropane triacrylate,
ethoxylated trimethylolpropane triacrylate, ethoxylated
trimethylolpropane triacrylate, trimethylolpropane triacrylate,
propoxylated trimethylolpropane triacrylate, pentaerythritol
triacrylate, ethoxylated pentaerythritol tetraacrylate, ethoxylated
pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate,
ditrimethylolpropane tetraacrylate, propoxylated pentaerythritol
tetraacrylate, pentaerythritol tetraacrylate, dipentaerythritol
hexaacrylate, 2,2,2-trisacryloyloxymethylethyl succinic acid,
2,2,2-trisacryloyloxymethylethyl phthalic acid, propoxylated
ditrimethylolpropane tetraacrylate, propoxylated dipentaerythritol
hexaacrylate, ethoxylated isocyanuric acid triacrylate,
.epsilon.-caprolactone denatured
tris-(2-acryloxyethyl)isocyanurate, caprolactone denatured
ditrimethylolpropane tetraacrylate, a compound represented by
General Formula (7):
##STR00007##
(wherein a+b=6, and n=12), a compound represented by General
Formula (8):
##STR00008##
(wherein a+b=4, and n=4), a compound represented by General Formula
(9):
##STR00009##
a compound represented by General Formula (10):
##STR00010##
(wherein m=1, a=2, and b=4; or m=1, a=3, and b=3; or m=1, a=6, and
b=0; or m=2, a=6, and b=0), a compound represented by General
Formula (11):
##STR00011##
(wherein a+b+c=3.6), a compound represented by General Formula
(12):
##STR00012##
and a compound represented by General Formula (13):
##STR00013##
(wherein ma=3 and a+b=3; "ma" is a product of m and a).
[0106] Furthermore, compounds having a hydroxyl group and/or a
carbonyl group in a molecular structural skeleton, such as
2-hydroxy-3-phenoxypropyl acrylate, phthalic acid monohydroxyethyl
acrylate, .omega.-carboxy-polycaprolactone monoacrylate, acrylic
acid dimer, pentaerythritol triacrylate, and pentaerythritol
tetraacrylate are also preferably used.
[0107] Further, any other photosensitive resin, for example,
epoxy-denatured acrylic (methacrylic) resins, urethane-denatured
acrylic (methacrylic) resins, and polyester-denatured acrylic
(methacrylic) resins, can be also used.
[0108] The photosensitive resin may be used solely. However, it is
preferable to use two or more types of the photosensitive resins in
combination, from the viewpoint of improving heat resistance of a
cured film obtained after photo-curing.
[0109] <(D) Photopolymerization Initiator>
[0110] The (D) photopolymerization initiator in the present
invention is a compound that is activated by energy of UV or the
like, and initiates and promotes a reaction of a photosensitive
resin. Examples of the (D) photopolymerization initiator encompass
Michler's ketone, [0111] 4,4'-bis(diethylamino)benzophenone,
4,4',4''-tris(dimethylamino)triphenylmethane, 2,2'-bis
(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-diimidazole,
acetophenone, benzoin, 2-methylbenzoin, benzoin methyl ether,
benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl
ether, 2-t-butylanthraquinone, 1,2-benzo-9,10-anthraquinone,
methylanthraquinone, thioxanthone, 2,4-diethylthioxanthone,
2-isopropylthioxanthone, 1-hydroxycyclohexyl phenyl ketone,
diacetylbenzyl, benzyl dimethyl ketal, benzyl diethyl ketal,
2(2'-furilethylidene)-4,6-bis(trichloromethyl)-S-triazine,
2[2'(5''-methylfuril)ethylidene]-4,6-bis(trichloromethyl)-S-triazine,
2(p-methoxyphenyl)-4,6-bis(trichloromethyl)-S-triazine,
2,6-di(p-azidobenzal)-4-methylcyclohexanone, 4,4'-diazidochalcon,
di(tetraalkylammonium)-4,4'-diazidostilbene-2,2'-disulfonate,
2,2-dimethoxy-1,2-diphenylethane-1-one,
1-hydroxy-cyclohexyl-phenyl-ketone,
2-hydroxy-2-methyl-1-phenyl-propane-1-one,
1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one,
2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1-one,
2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butane-1-one,
bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide,
bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide,
2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide,
2-hydroxy-2-methyl-1-phenyl-propane-1-ketone,
bis(n5-2,4-cyclopentadiene-1-yl)-bis(2,6-difluoro-3-(1H-pyrrole-1-yl)-phe-
nyl)titanium, 1,2-octanonedione,
1-[4-(phenylthio)-,2-(O-benzoyloxime)], iodonium,
(4-methylphenyl)[4-(2-methylpropyl)phenyl]-hexafluorophosphate(-
1-), ethyl-4-dimethylaminobenzoate,
2-ethylhexyl-4-dimethylaminobenzoate, ethanone, and
1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime).
The photopolymerization initiator is selected from among them, and
further, it is preferable that one or more of the
photopolymerization initiators be used in combination.
[0112] In the photosensitive resin composition of the present
invention, it is preferable that the component (A), the component
(B), the component (C), and the component (D) be mixed such that,
relative to 100 parts by weight of a total solid content of the
components (A) and (B), the component (C) is mixed by 10 to 200
parts by weight, and the component (D) is mixed by 0.1 to 50 parts
by weight.
[0113] The above content ratio is preferable because a cured
product and an insulting film that are ultimately obtained are
improved in various properties (electrical insulating reliability
and the like).
[0114] In a case where the amount of the (C) photosensitive resin
is less than the above range, heat resistance of a cured coating
film obtained by photo-curing the photosensitive resin composition
is decreased and contrast of the cured coating film is not easily
obtained when the cured coating film is exposed and developed.
Therefore, such an amount of the (C) photosensitive resin is not
preferable in some cases. When the (C) photosensitive resin is
contained in the above range, it is possible to attain resolution
of the cured coating film in an optimum range when the cured
coating film is exposed and developed.
[0115] Further, in a case where the amount of the (D)
photopolymerization initiator is less than the above range, it may
become difficult to cause a curing reaction of an acrylic resin
upon light irradiation, thereby often causing insufficient curing.
In the meantime, if the (D) photopolymerization initiator is
contained too much, it is difficult to adjust an irradiation amount
of light, thereby causing overexposure in some cases. In view of
this, in order to promote a photo-curing reaction effectively, it
is preferable to adjust the amount of the (D) photopolymerization
initiator in the above range.
[0116] <Other Components>
[0117] In order to improve adhesiveness and hardness of a cured
film, an inorganic filler can be further used in the photosensitive
resin composition of the present invention. The inorganic filler is
not particularly limited, but may be, for example, barium sulfate,
barium titanate, talc, ultrafine particulate anhydrous silica,
synthetic silica, natural silica, calcium carbonate, magnesium
carbonate, aluminum oxide, or the like. These can be used solely,
or two or more thereof can be used in combination.
[0118] Further, the photosensitive resin composition of the present
invention may include various additives, if necessary, such as a
defoaming agent, a leveling agent, a flame retardant, a coloring
agent, a tackifier, a polymerization inhibitor, and the like. These
additives are not limited particularly. For example, the defoaming
agent may be a silicon-based compound or an acryl-based compound,
and the leveling agent may be a silicon-based compound or an
acryl-based compound. Further, the flame retardant may be, for
example, a phosphoric ester-based compound, a halogen-based
compound, a metal hydroxide, an organophosphate-based compound, or
the like. As the coloring agent, a phthalocyanine-based compound,
an azo-based compound, carbon black, or oxidized titanium can be
used. Further, the tackifier may be, for example, a silane coupling
agent, a triazole-based compound, a tetrazole-based compound, a
triazine-based compound, or the like. Moreover, as the
polymerization inhibitor, hydroquinone, hydroquinone
monomethylether or the like can be used. These additives can be
used solely, or two or more types thereof can be used in
combination.
[0119] <Method for Mixing (A) to (D)>
[0120] The photosensitive resin composition of the present
invention can be prepared by uniformly mixing the aforementioned
components (A) to (D), and any of the above other components if
necessary. A method for uniformly mixing these components may be
carried out by use of, for example, a general mixing device such as
a three-roll or beads-mill device Further, in a case where an
obtainable solution has a low viscosity, it is also possible to use
a general stirring device to mix these components.
[0121] (III) Resin Composition Solution
[0122] A resin composition solution of the present invention
prepared by dissolving, into an organic solvent, the thermosetting
resin composition and the photosensitive resin composition is also
included in the present invention. The thermosetting resin
composition and the photosensitive resin composition are highly
soluble in various organic solvents. Examples of the organic
solvents encompass: sulfoxide-based solvents such as dimethyl
sulfoxide and diethyl sulfoxide; formamide-based solvents such as
N,N-dimethyl formamide and N,N-diethyl formamide; acetamide-based
solvents such as N,N-dimethylacetamide and N,N-diethylacetamide;
pyrrolidone-based solvents such as N-methyl-2-pyrrolidone and
N-vinyl-2-pyrrolidone; phenol-based solvents such as phenol, o-,
m-, or p-cresol, xylenol, halogenated phenol, and catechol;
solvents of symmetric glycol diethers such as
hexamethylphosphoramide, .gamma.-butyrolactone, methyl monoglyme
(1,2-dimethoxyethane), methyl diglyme (bis(2-methoxyethyl)ether),
methyl triglyme (1,2-bis(2-methoxyethoxy)ethane), methyl tetraglyme
(bis[2-(2-methoxyethoxyethyl)]ether), ethyl monoglyme
(1,2-diethoxyethane), ethyl diglyme (bis(2-ethoxyethyl)ether), and
butyl diglyme (bis(2-butoxyethyl)ether); solvents of acetates such
as .gamma.-butyrolactone, N-methyl-2-pyrrolidone, methyl acetate,
ethyl acetate, isopropyl acetate, n-propyl acetate, butyl acetate,
propylene glycol monomethyl ether acetate, ethylene glycol
monobutyl ether acetate, diethylene glycol monoethyl ether acetate
(another name: carbitol acetate, 2-(2-butoxyethoxy)ethyl)acetate),
diethylene glycol monobutyl ether acetate, 3-methoxybutyl acetate,
ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl
ether acetate, dipropylene glycol methyl ether acetate, propylene
glycol diacetate, and 1,3-butylene glycol diacetate; and solvents
of ethers such as dipropylene glycol methyl ether, tripropylene
glycol methyl ether, propylene glycol n-propyl ether, dipropylene
glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene
glycol n-butyl ether, tripylene glycol n-propyl ether, propylene
glycol phenyl ether, dipropylene glycol dimethyl ether,
1,3-dioxolan, ethylene glycol monobutyl ether, diethylene glycol
monoethyl ether, diethylene glycol monobutyl ether, and ethylene
glycol monoethyl ether. Note that hexane, acetone, toluene, xylene
or the like may be used in combination if necessary.
[0123] Among these solvents, the solvents of the symmetric glycol
diethers are particularly preferable because the photosensitive
resin composition is highly soluble therein.
[0124] In the resin composition of the present invention prepared
by dissolving, into an organic solvent, the thermosetting resin
composition and the photosensitive resin composition, it is
preferable that the organic solvent be mixed therein by not less
than 10 parts by weight but not more than 100 parts by weight,
relative to 100 parts by weight of a total solid content of the
components (A) and (B) or the components (A) to (D).
[0125] The resin composition solution prepared in the above range
is preferable because a rate of reduction in film thickness after
drying is small.
[0126] (IV) Use of Thermosetting Resin Composition
[0127] The thermosetting resin composition of the present invention
can be formed into a cured film or patterned as follows directly or
after the thermosetting resin composition solution is prepared.
Initially, the thermosetting resin composition is applied to a
substrate. Alternatively, the thermosetting resin composition
solution is applied to a substrate, and is dried so as to remove an
organic solvent. The application of the thermosetting resin
composition or the thermosetting resin composition solution to the
substrate may be carried out by screen printing, curtain rolling,
reverse rolling, spray coating, rotational application by use of a
spinner, or the like. An obtained applied film (having a thickness
of preferably 5 to 100 .mu.m, especially preferably 10 to 100
.mu.m) is dried at not more than 120.degree. C., preferably at 40
to 100.degree. C. Subsequently, the applied film is subjected to a
thermal curing treatment. Thus, a cured film having excellent heat
resistance and flexibility can be prepared. In a case where the
cured film is used as an insulating film for a printed wiring
board, a thickness of the cured film is determined in consideration
of a thickness of wiring lines and the like, but is preferably
about 2 to 50 .mu.m. As for a final curing temperature in the
thermal curing treatment, it is desirable that the curing be
carried out by heating at a low temperature so as to prevent
oxidization of the wiring lines and the like and a decrease in
adhesiveness of the wiring lines to a base material. In view of
this, a thermal curing temperature is preferably not less than
100.degree. C. but not more than 250.degree. C., more preferably
not less than 120.degree. C. but not more than 200.degree. C.,
particularly preferably not less than 130.degree. C. but not more
than 190.degree. C. The higher a final heat temperature is, the
more deterioration of the wiring lines due to oxidation may be
promoted.
[0128] The cured film formed by use of the thermosetting resin
composition of the present invention is excellent in heat
resistance, chemical resistance, and electrical and mechanical
properties, and especially in flexibility. For example, an
insulating film of the present invention has a thickness of
preferably about 2 to 50 .mu.m. In view of this, the insulating
film of the present invention is especially suitable as an
insulating material for a high-density flexible substrate.
Furthermore, the insulating film of the present invention is
applicable to various types of heat-curable wiring coating
protective agents, thermosetting heat-resistant adhesives,
insulating coatings of an electric wire and cable, and the
like.
[0129] In the present invention, it is also possible to provide a
similar insulating material with the use of a thermosetting film
obtainable by applying the thermosetting resin composition to a
surface of a base material, and drying the thermosetting resin
composition thus applied.
[0130] (V) Use of Photosensitive Resin Composition
[0131] The photosensitive resin composition of the present
invention can be patterned as follows. Initially, the
photosensitive resin composition is applied to a substrate and then
dried so as to remove an organic solvent. The application of the
photosensitive resin composition to the substrate may be carried
out by screen printing, roller coating, curtain coating, spray
coating, rotational application by use of a spinner, or the like.
An obtained applied film (having a thickness of preferably 5 to 100
.mu.m) is dried at not more than 120.degree. C., preferably at 40
to 100.degree. C. After the applied film is dried, a negative
photomask is placed on the applied film thus dried, and the applied
film is irradiated with active light such as ultraviolet rays,
visible rays, electron beams, or the like. Then, a portion, in the
applied film, that is not exposed to light is washed with a
developing solution by a method such as a shower method, a paddle
method, a soaking method, an ultrasonic method, or the like method
so as to form a pattern. Since the time required for the pattern to
be exposed differs depending on (i) spray pressure and flow speed
of the developing device and (ii) a temperature of the developing
solution, it is preferable to find an optimum condition for the
device as appropriate.
[0132] As the developing solution, an alkaline aqueous solution is
preferably used. The developing solution may contain a
water-soluble organic solvent such as methanol, ethanol,
n-propanol, isopropanol, or N-methyl-2-pyrrolidone. Examples of
alkaline compounds used for preparing the alkaline aqueous solution
encompass hydroxides, carbonates, hydrogencarbonates, or amine
compounds of alkaline metals, alkaline earth metals, or ammonium
ion, for example. More specifically, examples of the alkaline
compounds encompass sodium hydroxide, potassium hydroxide, ammonium
hydroxide, sodium carbonate, potassium carbonate, ammonium
carbonate, sodium hydrogencarbonate, potassium hydrogencarbonate,
ammonium hydrogencarbonate, tetramethylammonium hydroxide,
tetraethylammonium hydroxide, tetrapropylammonium hydroxide,
tetraisopropylammonium hydroxide, N-methyldiethanolamine,
N-ethyldiethanolamine, N,N-dimethylethanolamine, triethanolamine,
triisopropanolamine, triisopropylamine, and the like. Further, any
other compounds are obviously usable as long as the aqueous
solution exhibits basicity.
[0133] The alkaline compound preferably used in the step of
developing the photosensitive resin composition of the present
invention has a concentration of preferably 0.01 to 10% by weight,
especially preferably 0.05 to 5% by weight. A temperature of the
developing solution depends on a composition of the photosensitive
resin composition and a composition of the developing solution.
Generally, the temperature of the developing solution is preferably
not less than 0.degree. C. but not more than 80.degree. C., more
preferably not less than 20.degree. C. but not more than 50.degree.
C.
[0134] The pattern thus formed in the developing step is rinsed to
remove unnecessary residues of the developing solution. Examples of
a rinsing fluid used for the rinse may be water and an acidic
aqueous solution.
[0135] After that, a resultant film is subjected to a
thermal-curing treatment. Thus, a cured film excellent in heat
resistance and flexibility can be obtained. In a case where the
cured film is used as an insulating film for a printed wiring
board, a thickness of the cured film is determined in consideration
of a thickness of wiring lines and the like, but is preferably
about 2 to 50 .mu.m. As for a final curing temperature in the
thermal-curing treatment, it is desirable that the thermal curing
be carried out at a low temperature so as to prevent oxidation of
the wiring lines and the like and a decrease in adhesiveness of the
wiring lines to a base material. The thermal-curing temperature at
this time is preferably not less than 100.degree. C. but not more
than 250.degree. C., further preferably not less than 120.degree.
C. but not more than 200.degree. C., particularly preferably not
less than 130.degree. C. but not more than 190.degree. C. If a
final heat temperature is high, deterioration of the wiring lines
due to oxidation may be promoted in some cases.
[0136] The pattern of the cured film formed by use of the
photosensitive resin composition of the present invention is
excellent in heat resistance, chemical resistance, and electrical
and mechanical properties, and especially in flexibility. For
example, an insulating film of the present invention has a
thickness of preferably about 2 to 50 .mu.m. The insulating film
upon photo-curing has a resolution of at least up to 10 .mu.m, and
in particular, a resolution of about 10 to 1000 .mu.m. In view of
this, the insulating film of the present invention is especially
suitable as an insulating material for a high-density flexible
substrate. Furthermore, the insulating film of the present
invention is applicable to various types of photo-curable wiring
coating protective agents, photosensitive heat-resistant adhesives,
insulating coatings of an electric wire and cable, and the
like.
[0137] In the present invention, it is also possible to provide a
similar insulating material with the use of a photosensitive film
obtainable by applying the photosensitive resin composition to a
surface of a base material, and drying the photosensitive resin
composition thus applied.
EXAMPLES
[0138] The following describes Examples of the present invention,
more specifically. However, the present invention is not limited to
Examples as below.
Synthetic Example 1
Synthesis of Urethane Imide Oligomer Having Terminal Carboxylic
Acid Group
[0139] Into a separable flask under nitrogen pressure, methyl
triglyme (16.0 g) was poured as a solvent for polymerization. Then,
20.7 g (0.1004 mol) of norbornene diisocyanate was added thereto
and heated to 80.degree. C. so as to be dissolved in the methyl
triglyme. Into a resultant solution, there was added, over 1 hour,
a solution in which the following (a) and (b) components were
dissolved into methyl triglyme (40.0 g): (a) 8.1 g (0.050 mol) of
dimethylol butanoic acid (2,2-bis(hydroxymethyl) butanoic acid);
and (b) 50.0 g (0.025 mol) of a polycarbonate diol (manufactured by
Asahi Kasei Co., Ltd.: trade name PCDL T5652, a polycarbonate diol
having an average molecular weight of 2,000 and represented by
General Formula (14):
##STR00014##
wherein q, r, and s are an integer of not less than 1). A resultant
solution was refluxed under heating for 5 hours. A reactant
solution thus obtained is referred to as an intermediate A.
[0140] Into another reaction apparatus that was different from the
reaction apparatus used for the above reaction, there were added
52.0 g (0.100 mol) of
2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride
(hereinafter referred to as BPADA) and methyl triglyme (40.0 g).
This mixture was heated to 80.degree. C. so that the BPADA was
dispersed in the methyl triglyme.
[0141] Into a resultant solution, the intermediate A was added over
1 hour so that the intermediate A was reacted with the solution.
After the addition of the intermediate A was completed, a resultant
was heated to 200.degree. C. so that the reaction was carried out
for 3 hours. As a result of the reaction, a solution of a urethane
imide oligomer having a terminal acid anhydride was prepared. Into
this solution, 7.2 g (0.400 mol) of purified water was poured, and
refluxed under heating at 80.degree. C. for 5 hours. Thus, a
solution of a urethane imide oligomer having a terminal carboxylic
acid group was prepared. This synthetic resin is referred to as a
resin A.
Example 1
Preparation of Thermosetting Resin Composition Solution
[0142] The obtained solution (resin A) of the urethane imide
oligomer having a terminal carboxylic acid group was cooled down to
a room temperature. Into the solution, there was added 10 parts by
weight of an epoxy resin (manufactured by Dainippon Ink and
Chemical: trade name EPICLON N-665-EXP, a cresol novolac type
polyfunctional epoxy resin), relative to 100 parts by weight of a
resin content in the solution. A resultant solution was uniformly
stirred for 1 hour at the room temperature, so as to prepare a
thermosetting resin composition solution. The solution thus
prepared had a solute concentration of 60% and a viscosity of 230
poise at 23.degree. C.
[0143] <Evaluation of Storage Stability of Thermosetting Resin
Composition Solution>
[0144] In order to examine storage stability of the thermosetting
resin composition solution, the thermosetting resin composition
solution was hermetically sealed in a 10-ml screw tube, and left to
stand for 1 month in a chamber maintained at 20.degree. C. After 1
month, the viscosity of the solution was measured. The measured
viscosity at that time was 230 poise at 23.degree. C., and thus no
change in viscosity was observed. It was accordingly demonstrated
that the thermosetting resin composition solution was storable for
a long period of time at the room temperature.
[0145] <Preparation of Cured Film on Polyimide Film>
[0146] With the use of a Baker's applicator, the thermosetting
resin composition solution was flow-cast and applied to a polyimide
film (manufactured by Kaneka Corporation: trade name 75NPI) having
a thickness of 75 .mu.m so that a finally dried film had a
thickness of 25 .mu.m. A resultant coating film was dried at
80.degree. C. for 20 minutes, thereby preparing a resin film of the
present invention on the polyimide film as a base. The resin film
thus prepared was cured by heating at 160.degree. C. for 90 minutes
in the air so that the resin film was formed into a cured film. In
this way, a polyimide film laminate in which the cured film was
provided on the polyimide film as a base was prepared.
[0147] <Evaluation of Cured Film>
[0148] The cured film thus prepared was evaluated in terms of the
following items. Evaluation results are shown in Table 1.
[0149] (i) Adhesiveness of Cured Film
[0150] Adhesive strength of the cured film thus prepared was
evaluated by a cross-cut tape method in accordance with JIS K5400,
as follows:
(I) A cured film in which no detachment was observed in the
cross-cut tape method was evaluated as "G (Good)"; (II) A cured
film in which half or more of grids remained was evaluated as "U
(Unsatisfactory)"; and (III) A cured film in which less than half
of grids remained was evaluated as "P (Poor)".
[0151] (ii) Stability of Cured Film in Environmental Resistance
Test
[0152] If a cured film is not sufficiently cured by heating,
stability of the cured film in an environmental test apparatus is
decreased. In view of this, the stability, of the cured film thus
prepared, in the environmental test apparatus was measured. With
the use of a thermo-hygrostat Type: PR-1K, manufactured by ESPEC
Corp., as the environmental test apparatus, evaluation was carried
out such that a cured film provided on a polyimide film was
subjected to an environment at 85.degree. C./85% RH for 1000 hours,
and then a condition of the cured film was observed. The evaluation
was carried out as follows:
(I) A cured film having no change was evaluated as "G (Good)"; (II)
A cured film that was partially dissolved was evaluated as "U
(Unsatisfactory)"; and (III) A cured film that was completely
dissolved was evaluated as "P (Poor)".
[0153] (iii) Chemical Resistance
[0154] Evaluation of chemical resistance was carried out on a
surface of the cured film. The evaluation was carried out based on
the following evaluation items 1 to 3 in such a manner that the
polyimide film laminate was soaked and a surface of the cured film
was observed.
Evaluation Item 1: A polyimide film laminate was soaked in
methylethyl ketone at 25.degree. C. for 10 minutes, and then dried
by air. Evaluation Item 2: A polyimide film laminate was soaked in
a 2N hydrochloric acid solution at 25.degree. C. for 10 minutes.
The polyimide film laminate was then washed with purified water and
dried by air. Evaluation Item 3: A polyimide film laminate was
soaked in a 2N sodium hydroxide solution at 25.degree. C. for 10
minutes. The polyimide film laminate was washed with purified water
and then dried by air. The evaluation was carried out as follows:
(I) A cured film having no change was evaluated as "G (Good)"; (II)
A cured film that was partially dissolved was evaluated as "U
(Unsatisfactory)"; and (III) A cured film that was completely
dissolved was evaluated as "P (Poor)".
[0155] (vi) Flexibility Evaluation
[0156] The thermosetting resin composition solution was applied to
a surface of a polyimide film (Apical 25NPI, manufactured by Kaneka
Corporation) having a thickness of 25 .mu.m so as to have a final
film thickness of 25 .mu.m. A resultant coating film was dried at
80.degree. C. for 20 minutes, and then 160.degree. C. for 90
minutes. Thus, a polyimide film laminate was prepared. The
polyimide film laminate was cut out into strips of 30 mm.times.10
mm. Each of the strips was bent in the middle (at a point 15 mm
from its edge) by 180.degree. for 10 times. Then, a coating film
(cured film) of each of the strips was observed with eyes to
examine whether or not a crack occurred. The evaluation was carried
out based on definition as follows:
(I) "G (Good)" indicates a cured film having no crack; (II) "U
(Unsatisfactory)" indicates a cured film having a slight crack; and
(III) "P (Poor)" indicates a cured film having a crack.
[0157] (v) Wettability
Wettability of the cured film prepared in the aforementioned
<Preparation of Cured Film on Polyimide Film> was measured in
accordance with a JIS K6768 measuring method.
TABLE-US-00001 TABLE 1 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Adhesiveness G G G G
Of Coating Film Stability of Film in G G G G Environmental
Resistance Test Chemical Evaluation G G G G Resistance Item 1
Evaluation G G G G Item 2 Evaluation G G G G Item 3 Flexibility
Evaluation G G G G Wettability (mN/m) 38 38 38 36 Abbreviation: Ex.
stands for Example. G stands for Good.
Synthesis Example 2
[0158] A resin was prepared in the same manner as Synthesis
[0159] Example 1 except that, instead of adding 7.2 g (0.400 mol)
of purified water, 12.8 g (0.400 mol) of methanol was added to a
mixture obtained after a reaction was completed, so that the
mixture was half-esterified. Thus, a solution of a urethane imide
oligomer having a terminal carboxylic acid group was prepared. The
resin thus synthesized in this manner is referred to as a resin
B.
Example 2
Preparation of Thermosetting Resin Composition Solution
[0160] The prepared solution (resin B) of the urethane imide
oligomer having a terminal carboxylic acid group was cooled down to
a room temperature. Into the solution, there was added 10 parts by
weight of an epoxy resin (manufactured by Dainippon Ink and
Chemicals: trade name EPICLON N-665-EXP, a cresol novolac type
polyfunctional epoxy resin), relative to 100 parts by weight of a
resin content in the solution. A resultant solution was uniformly
stirred for 1 hour at the room temperature, so as to prepare a
thermosetting resin composition solution. The solution thus
prepared had a solute concentration of 60% and a viscosity of 220
poise at 23.degree. C.
[0161] <Evaluation of Storage Stability of Thermosetting Resin
Composition Solution>
[0162] In order to examine storage stability of the thermosetting
resin composition solution, the thermosetting resin composition
solution was hermetically sealed in a 10-ml screw tube, and left to
stand for 1 month in a chamber maintained at 20.degree. C. After 1
month, the viscosity of the solution was measured. The measured
viscosity at that time was 220 poise at 23.degree. C., and thus no
change in viscosity was observed. It was accordingly demonstrated
that the thermosetting resin composition solution was storable for
a long period of time at the room temperature.
[0163] Further, a cured film obtained from the thermosetting resin
composition was evaluated in the same manner as the evaluation
method of Example 1. Evaluation results are shown in Table 1.
Example 3
Preparation of Thermosetting Resin Composition Solution
[0164] Into the solution (resin A) of the urethane imide oligomer
having a terminal carboxylic acid group, which was obtained in
Example 1, there was added 10 parts by weight of an epoxy resin
(manufactured by Nippon Kayaku Co., Ltd.: trade name NC-3000H, a
biphenyl novolac type polyfunctional epoxy resin), relative to 100
parts by weight of a resin content in the solution. A resultant
solution was uniformly stirred for 1 hour at the room temperature,
so as to prepare a thermosetting resin composition solution. The
solution thus prepared had a solute concentration of 60% and a
viscosity of 250 poise at 23.degree. C.
[0165] <Evaluation of Storage Stability of Thermosetting Resin
Composition Solution>
[0166] In order to examine storage stability of the thermosetting
resin composition solution, the thermosetting resin composition
solution was hermetically sealed in a 10-ml screw tube, and left to
stand for 1 month in a chamber maintained at 20.degree. C. After 1
month, the viscosity of the solution was measured. The measured
viscosity at that time was 250 poise at 23.degree. C., and thus no
change in viscosity was observed. It was accordingly demonstrated
that the thermosetting resin composition solution was storable for
a long period of time at the room temperature.
Further, a cured film obtained from the thermosetting resin
composition was evaluated in the same manner as the evaluation
method of Example 1. Evaluation results are shown in Table 1.
Example 4
Preparation of Thermosetting Resin Composition Solution
[0167] Into the solution (resin A) of the urethane imide oligomer
having a terminal carboxylic acid group, which was obtained in
Example 1, there was added 10 parts by weight of an oxetane resin
(manufactured by Toagosei Co., Ltd.: trade name Aron Oxetane
OXT-121, 1,4-bix{[(3-ethyl-3-oxetanyl)methoxy]methyl}benzene),
relative to 100 parts by weight of a resin content in the solution.
A resultant solution was uniformly stirred for 1 hour at the room
temperature, so as to prepare a thermosetting resin composition
solution. The solution thus prepared had a solute concentration of
60% and a viscosity of 180 poise at 23.degree. C.
[0168] <Evaluation of Storage Stability of Thermosetting Resin
Composition Solution>
[0169] In order to examine storage stability of the thermosetting
resin composition solution, the thermosetting resin composition
solution was hermetically sealed in a 10-ml screw tube, and left to
stand for 1 month in a chamber maintained at 20.degree. C. After 1
month, the viscosity of the solution was measured. The measured
viscosity at that time was 180 poise at 23.degree. C., and thus no
change in viscosity was observed. It was accordingly demonstrated
that the thermosetting resin composition solution was storable for
a long period of time at the room temperature.
[0170] Further, a cured film obtained from the thermosetting resin
composition was evaluated in the same manner as the evaluation
method of Example 1. Evaluation results are shown in Table 1.
Comparative Synthesis Example 1
[0171] Into a 5-litter, 4-necked flask equipped with a stirrer, a
condenser, a nitrogen-inlet tube, and a thermometer, there were
added 227.5 g (0.909 mol) of diphenylmethane-2,4'-diisocyanate,
227.5 g (0.909 mol) of diphenylmethane-4,4'-diisocyanate, 644.9 g
(1.8 mol) of 3,3',4,4'-diphenylsulfone tetracarboxylic acid
dianhydride, and 1649.9 g of .gamma.-butyrolactone. A resultant
mixture was heated to 170.degree. C. and reacted for 6 hours,
thereby preparing a resin having a number-average molecular weight
of 15,000. The resin thus synthesized is referred to as a resin C.
The resin thus prepared was diluted with .gamma.-butyrolactone.
Then, 22.8 g of 2-butanone oxime was added thereto, and a resultant
was heated at 90.degree. C. for 3 hours, thereby preparing a
polyamide imide resin solution having a nonvolatile content of 30%
by weight.
Comparative Example 1
Preparation of Thermosetting Resin Composition Solution
[0172] Into the prepared polyamide imide resin solution, there was
added 5 parts by weight of an epoxy resin (manufactured by Tohto
Kasei Co., Ltd.: trade name YDF-170, a bisphenol F type epoxy
resin), relative to 100 parts by weight of a resin content in the
solution. A resultant solution was diluted with
.gamma.-butyrolactone, and uniformly stirred for 1 hour at a room
temperature, thereby preparing a thermosetting resin composition
solution. The solution had a solute concentration of 30% and a
viscosity of 200 poise at 23.degree. C.
[0173] <Evaluation of Storage Stability of Thermosetting Resin
Composition Solution>
[0174] In order to examine storage stability of the thermosetting
resin composition solution, the thermosetting resin composition
solution was hermetically sealed in a 10-ml screw tube, and left to
stand for 1 month in a chamber maintained at 20.degree. C. After 1
month, the solution was gelatinized and the viscosity thereof was
unmeasurable. Thus, it was demonstrated that this solution had poor
storage stability at the room temperature.
[0175] Further, a cured film obtained from the thermosetting resin
composition was evaluated in the same manner as the evaluation
method of Example 1. Evaluation results are shown in Table 2.
Comparative Synthesis Example 2
[0176] Diphenylmethane-4,4'-diisocyanate (1.0 mol),
diphenylmethane-2,4'-diisocyanate (1.0 mol), and poly(hexamethylene
carbonate) (0.8 mol) having an average molecular weight of 2,000
were reacted with each other in 1-methyl-2-pyrrolidone under a
nitrogen atmosphere at 100.degree. C. for 1 hour. Then,
4,4'-oxydiphthalic acid anhydride (1.0 mol), triethylamine, and
1-methyl-2-pyrrolidone were added thereto, and a resultant mixture
was further stirred at 100.degree. C. for 3 hours. Further, benzyl
alcohol was added to the mixture and stirred at 100.degree. C. for
1 hour, and a reaction was completed. A resultant solution was
poured into water that was stirred intensely so as to filter the
resultant solution to separate a precipitate. The precipitate was
then dried in vacuum at 80.degree. C. for 8 hours, so as to obtain
a polyurethane imide resin. The resin thus synthesized is referred
to as a resin D. The polyurethane imide resin thus obtained was
measured by use of GPC. As a result of the measurement, the
polyurethane imide resin was such that Mw=55,000 and Mn=25,000,
based on polystyrene.
Comparative Example 2
Preparation of Thermosetting Resin Composition Solution
[0177] The prepared polyurethane imide resin was dissolved in
methylethyl ketone so as to have a solute concentration of 40% by
weight, thereby preparing a polyurethane imide resin solution.
Then, into the polyurethane imide resin solution, there were added
25 parts by weight of a urethane acrylate resin (manufactured by
Shin-Nakamura Chemical Co., Ltd.: trade name U-108) and, as a
curing agent, 3.75 parts by weight of 1,1-bis(t-hexyl
peroxy)-3,3,5-trimethyl cyclohexane (manufactured by Nippon Yushi
K.K.: trade name Perhexa TMH), relative to 100 parts by weight of a
resin content in the solution. A resultant mixture was uniformly
stirred for 1 hour at a room temperature, thereby preparing a
thermosetting resin composition solution. The solution thus
prepared had a solute concentration of 40% and a viscosity of 1200
poise at 23.degree. C. As such, the solution was very viscous.
[0178] <Evaluation of Storage Stability of Thermosetting Resin
Composition Solution>
[0179] In order to examine storage stability of the thermosetting
resin composition solution, the thermosetting resin composition
solution was hermetically sealed in a 10-ml screw tube, and left to
stand for 1 month in a chamber maintained at 20.degree. C. After 1
month, the solution was gelatinized and the viscosity thereof was
unmeasurable. Thus, it was demonstrated that this solution had poor
storage stability at the room temperature.
[0180] Further, a cured film obtained from the thermosetting resin
composition was evaluated in the same manner as the evaluation
method of Example 1. Evaluation results are shown in Table 2.
Comparative Synthesis Example 3
[0181] Into a flask equipped with a stirrer, a thermometer, and a
condenser, there were added 1496 parts of EDGA (diethylene glycol
monomethylether acetate), 888 parts (4 mol) of IPDI (isophorone
diisocyanate), and 960 parts (5 mol) of trimellitic anhydride, and
a temperature of the flask was increased to 160.degree. C. A
reaction of these substances was promoted while foaming. The
reaction was carried out for 4 hours while the temperature was
maintained at 160.degree. C. In the reaction system, a clear liquid
in light brown color was obtained. The clear liquid thus obtained
was subjected to a characteristic absorption measurement by use of
infrared spectrum. As a result of the measurement, characteristic
absorption of an isocyanate group at 2270 cm.sup.-1 was completely
disappeared, and absorption of an imide group at 725 cm.sup.-1,
1780 cm.sup.-1, and 1720 cm.sup.-1 was observed. The resin thus
synthesized is referred to as a resin E. The resin E had an acid
number of 85 KOHmg/g based on a solid content. As for a molecular
weight of the resin E, the resin E had a number-average molecular
weight of 1,600 based on polystyrene.
Comparative Example 3
Preparation of Thermosetting Resin Composition Solution
[0182] Into a terminal carboxylic acid imide oligomer solution thus
prepared, there was added 38.50 g of an epoxy resin (manufactured
by Dainippon Ink and Chemicals: trade name EPICLON N-665-EXP, a
cresol novolac type polyfunctional epoxy resin), relative to 100
parts by weight of a resin content in the solution. A resultant
solution was uniformly stirred for 1 hour at a room temperature,
thereby preparing a thermosetting resin composition solution. The
solution thus prepared had a solute concentration of 68% and a
viscosity of 250 poise at 23.degree. C.
[0183] <Evaluation of Storage Stability of Thermosetting Resin
Composition Solution>
[0184] In order to examine storage stability of the thermosetting
resin composition solution, the thermosetting resin composition
solution was hermetically sealed in a 10-ml screw tube, and left to
stand for 1 month in a chamber maintained at 20.degree. C. After 1
month, the solution was gelatinized and the viscosity thereof was
unmeasurable. Thus, it was demonstrated that this solution had poor
storage stability at the room temperature.
[0185] Further, a cured film obtained from the thermosetting resin
composition was evaluated in the same manner as the evaluation
method of Example 1. Evaluation results are shown in Table 2.
Comparative Synthesis Example 4
[0186] Initially, air in a 4-necked flask was replaced with
nitrogen, and a stirrer, a nitrogen-inlet tube, a reflux condenser,
and a stopper were attached to the flask. Then, into the flask,
20.23 g (68.76 mmol) of 2,3,3',4'-biphenyltetracarboxylic acid
dianhydride and 30 g of methanol were added and refluxed. After 3
hours, a temperature in the flask was cooled down to a room
temperature, and the reflux condenser was replaced with a reflux
condenser equipped with a mist separator. Subsequently, 0.07 g of a
defoaming agent (made by Dow Corning Asia Ltd.: trade name FS
Antifoam DB-100) and 31.01 g (34.38 mmol) of amino-denatured
silicone oil (made by Dow Corning Toray Silicone Company Ltd.:
trade name BY16-853U, amine number of 451) were added to the flask,
and methanol was distilled away over 1 hour. After that, the
temperature in the flask was increased to 190.degree. C., and a
reaction was carried out for 1 hour while water was distilled away,
so as to prepare 48.75 g (yield: 97.50%) of a viscous product in
brownish-red color. The resin thus synthesized is referred to as a
resin F. The resin had a viscous of 392 poise at 80.degree. C.
Comparative Example 4
Preparation of Thermosetting Resin Composition Solution
[0187] A siloxane imide resin having a terminal acid anhydride,
prepared in the above manner, was dissolved in methylethyl ketone
so as to have a solute concentration of 40% by weight, thereby
preparing a solution of the siloxane imide resin having a terminal
acid anhydride. Then, into the solution, there were added 100 parts
by weight of an epoxy resin (made by Japan Epoxy Resins Co., Ltd.:
trade name jER 828, a bisphenol A type bifunctional epoxy resin),
116 parts by weight of a curing agent of a cycloaliphatic acid
anhydride type (Japan Epoxy Resins Co., Ltd.: trade name Epicure
YH306), and 1 part by weight of an accelerator catalyst (made by
Shikoku Chemical Corporation: trade name Curezole 2E4MZ, an
imidazole compound), relative to 24 parts by weight of a resin
content in the solution. A resultant mixture was uniformly stirred
for 1 hour at a room temperature, so as to prepare a thermosetting
resin composition solution. The solution had a solute concentration
of 87% and a viscosity of 320 poise at 23.degree. C.
[0188] <Evaluation of Storage Stability of Thermosetting Resin
Composition Solution>
[0189] In order to examine storage stability of the thermosetting
resin composition solution, the thermosetting resin composition
solution was hermetically sealed in a 10-ml screw tube, and left to
stand for 1 month in a chamber maintained at 20.degree. C. After 1
month, the solution was gelatinized and the viscosity thereof was
unmeasurable. Thus, it was demonstrated that this solution had poor
storage stability at the room temperature.
[0190] Further, a cured film obtained from the thermosetting resin
composition was evaluated in the same manner as the evaluation
method of Example 1. Evaluation results are shown in Table 2.
TABLE-US-00002 TABLE 2 Com. Ex. 1 Com. Ex. 2 Com. Ex. 3 Com. Ex. 4
Adhesiveness G G G U Of Coating Film Stability of Film in P P G G
Environmental Resistance Test Chemical Evaluation U U G G
Resistance Item 1 Evaluation G G G G Item 2 Evaluation G G G G Item
3 Flexibility Evaluation G G P P Wettability (mN/m) 38 36 38 30 or
less Abbreviation: Com. Ex. stands for Comparative Example; G
stands for Good; U stands for Unsatisfactory; and P stands for
Poor.
Comparative Synthesis Example 5
Synthesis of Urethane Imide Oligomer Having Terminal Acid
Anhydride
[0191] Into a separable flask under nitrogen pressure, methyl
triglyme (16.0 g) was added as a solvent for polymerization. Then,
20.7 g (0.1004 mol) of norbornene diisocyanate was added thereto
and heated to 80.degree. C. so as to be dissolved in the methyl
triglyme. Into a resultant solution, there was added, over 1 hour,
a solution in which the following (a) and (b) components were
dissolved into methyl triglyme (40.0 g): (a) 8.1 g (0.050 mol) of
dimethylol butanoic acid (2,2-bis(hydroxymethyl)butanoic acid); and
(b) 50.0 g (0.025 mol) of polycarbonate diol (manufactured by Asahi
Kasei Co., Ltd.: trade name PCDL T5652, a polycarbonate diol having
an average molecular weight of 2,000 and represented by General
Formula (14):
##STR00015##
wherein q, r, and s are an integer of not less than 1). A resultant
solution was refluxed under heating for 5 hours. A reactant
solution thus obtained is referred to as an intermediate A.
[0192] Into another reaction apparatus that was different from the
reaction apparatus used for the above reaction, there were added
52.0 g (0.100 mol) of
2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride
(hereinafter referred to as BPADA) and methyl triglyme (40.0 g).
This mixture was heated to 80.degree. C. so that the BPADA was
dispersed in the methyl triglyme.
[0193] Into a resultant mixture, the intermediate A was added over
1 hour so that the intermediate A was reacted with the mixture.
After the addition of the intermediate A was completed, a resultant
was heated to 200.degree. C. so that the reaction was carried out
for 3 hours. As a result of the reaction, a solution of a urethane
imide oligomer having a terminal acid anhydride was prepared.
Comparative Example 5
Preparation of Thermosetting Resin Composition Solution
[0194] The solution of the urethane imide oligomer having a
terminal acid anhydride was cooled down to a room temperature. Into
the solution, there was added 10 parts by weight of an epoxy resin
(manufactured by Dainippon Ink and Chemical: trade name EPICLON
N-665-EXP, a cresol novolac type polyfunctional epoxy resin)
relative to 100 parts by weight of a resin content in the solution.
A resultant solution was uniformly stirred for 1 hour at the room
temperature, so as to prepare a thermosetting resin composition
solution. The solution thus prepared had a solute concentration of
60% and a viscosity of 240 poise at 23.degree. C.
[0195] <Evaluation of Storage Stability of Thermosetting Resin
Composition Solution>
[0196] In order to examine storage stability of the thermosetting
resin composition solution, the thermosetting resin composition
solution was hermetically sealed in a 10-ml screw tube, and left to
stand for 1 month in a chamber maintained at 20.degree. C. After 1
month, the solution was gelatinized and the viscosity thereof was
unmeasurable. Thus, it was demonstrated that this solution had poor
storage stability at the room temperature.
[0197] Further, evaluation on a cured film obtained from the
thermosetting resin composition was attempted in the same manner as
the evaluation method of Example 1. However, due to the
gelatinization of the thermosetting resin composition solution, it
was difficult to apply the solution onto a base material.
Consequently, a uniform cured film could not be obtained.
Examples 5 to 8
Preparation of Photosensitive Resin Composition
[0198] A (A) urethane imide oligomer having a terminal carboxylic
acid group, which was obtained in Synthesis Example 1 or 2, a (B)
thermosetting resin, a (C) photosensitive resin, a (D)
photopolymerization initiator, and other components were mixed to
prepare a photosensitive resin composition. Respective amounts of
constituent raw materials in terms of a resin solid content, and
types of the constituent raw materials are shown in Table 3. In
Table 3, the amount of 1,2-bis(2-methoxyethoxy)ethane as a solvent
indicates a total amount of solvent including a solvent contained
in the synthetic resin solution and the like. The mixed solution
was set in a defoaming device so that the solution was completely
defoamed. A resultant solution was then evaluated as follows.
TABLE-US-00003 TABLE 3 Unit: Part by Weight Component Ex. 5 Ex. 6
Ex. 7 Ex. 8 (A) Resin A 60.0 -- 60.0 60.0 Resin B -- 60.0 -- -- (B)
N-665-EXP <1> 10.0 10.0 -- -- NC-3000H <2> -- -- 10.0
-- OXT-121 <3> -- -- -- 10.0 (C) A-9300 <4> 3.0 3.0 3.0
3.0 BPE-1300 <5> 12.0 12.0 12.0 12.0 (D) IRGACURE 819
<6> 2.0 2.0 2.0 2.0 Others Barium Sulfate 12.0 12.0 12.0 12.0
Aerosil R-974 <7> 1.0 1.0 1.0 1.0 1,2-bis(2-methoxyethoxy)-
50 50 50 50 ethane Solid Content Concentration 66.6 66.6 66.6 66.6
of Photosensitive Resin Composition Solution <1> Cresol
novolac type polyfunctional epoxy resin, trade name: EPICLON
N-665-EXP, manufactured by Dainippon Ink and Chemicals <2>
Biphenyl novolac type polyfunctional epoxy resin, trade name:
NC-3000H, manufactured by Nippon Kayaku Co., Ltd. <3> Oxetane
resin, trade name: Aron Oxetane OXT-121, manufactured by Toagosei
Co., Ltd. <4> Ethoxylated isocyanuric acid triacrylate, trade
name: NK ester A-9300, manufactured by Shin-Nakamura Chemical Co.,
Ltd. <5> Bisphenol A EO-denatured diacrylate, trade name: NK
ester BPE-1300, manufactured by Shin-Nakamura Chemical Co., Ltd.
<6> Product manufactured by CIBA specialty chemicals Inc.:
Photopolymerization initiator <7> Product manufactured by
Nippon AEROSIL Co., Ltd.: Silica particles
[0199] <Preparation of Coating Film on Polyimide Film>
[0200] With the use of a Baker's applicator, each of the
photosensitive resin composition solutions thus prepared was
flow-cast and applied to a polyimide film (manufactured by Kaneka
Corporation: trade name 75NPI) having a thickness of 75 .mu.m in an
area of 100 mm.times.100 mm so as to have a final dried film
thickness of 25 .mu.m, and dried 80.degree. C. for 20 minutes. A
negative photomask having an area of 50 mm.times.50 mm with line
width/space width=100 .mu.m/100 .mu.m was placed thereon. Resultant
films were then exposed to ultraviolet rays having an integrated
exposure amount of 300 mJ/cm.sup.2. Then, the films were developed
by spraying a 1.0 weight % sodium carbonate aqueous solution heated
at 30.degree. C., at a spraying pressure of 1.0 kgf/mm.sup.2 for 60
seconds. After the development, the films were washed with purified
water sufficiently, and then cured by heating in an oven at
160.degree. C. for 90 minutes. Thus, cured films of the respective
photosensitive resin compositions were prepared.
[0201] <Evaluation of Cured Film>
[0202] The cured films thus prepared were evaluated in regard to
the following items. Evaluation results are shown in Table 4.
[0203] (i) Photosensitivity Evaluation
[0204] Photosensitivity of each of the photosensitive resin
compositions was evaluated by observing a surface of a
corresponding cured film prepared in the aforementioned item
<Preparation of Coating Film on Polyimide Film>. The
evaluation was based on definition as follows:
(I) "G (Good)" indicates a polyimide film in which a sensitive
pattern of line width/space width=100/100 .mu.m was clearly formed
on a surface thereof, no deformation of lines caused by detachment
of line portions occurred, and dissolution residues were not
observed on space portions; (II) "U (Unsatisfactory)" indicates a
polyimide film in which a sensitive pattern of line width/space
width=100/100 .mu.m was clearly formed on a surface thereof,
deformation of lines caused by detachment of line portions
occurred, but dissolution residues were not observed on space
portions; and (III) "P (Poor)" indicates a polyimide film in which
a sensitive pattern of line width/space width=100/100 .mu.m was not
clearly formed on a surface thereof, line portions were detached,
and dissolution residues were observed on space portions.
[0205] (ii) Adhesiveness of Cured Film
[0206] Adhesive strength of each of the cured films prepared in the
aforementioned item <Preparation of Coating Film on Polyimide
Film> was evaluated by a cross-cut tape method in accordance
with JIS K5400 as follows:
(I) "G (Good)" indicates a cured film in which no detachment was
observed in the cross-cut tape method; (II) "U (Unsatisfactory)"
indicates a cured film in which 95% or more of grids remained; and
(III) "P (Poor)" indicates a cured film in which the amount of
remaining grids was less than 80%.
[0207] (iii) Solvent Resistance
[0208] Solvent resistance of each of the cured films prepared in
the aforementioned item <Preparation of Coating Film on
Polyimide Film> was evaluated. The evaluation was carried out in
such a manner that after a cured film was immersed in methylethyl
ketone at 25.degree. C. for 15 minutes, the cured film was dried by
air, and a surface of the cured film thus dried was observed. The
evaluation was based on definition as follows:
(I) "G (Good)" indicates a coating film (cured film) having no
problem; and (II) "P (Poor)" indicates a coating film (cured film)
having a problem such as swelling or detachment.
[0209] (iv) Flexibility
[0210] In the same manner as in the item <Preparation of Coating
Film on Polyimide Film>, each of the photosensitive resin
compositions was applied on a surface of a polyimide film (Apical
25 NPI manufactured by Kaneka Corporation) having a thickness of 25
.mu.m, so as to prepare a cured-film-laminated film. The
cured-film-laminated film was then cut out into strips of 30
mm.times.10 mm. Each of the strips was bent in the middle (at a
point 15 mm from its edge) by 180.degree. for 10 times. Then, a
coating film (cured film) of each of the strips was observed with
eyes to examine whether or not a crack occurred. The evaluation was
carried out based on definition as follows:
(I) "G (Good)" indicates a cured film having no crack; (II) "U
(Unsatisfactory)" indicates a cured film having a slight crack; and
(III) "P (Poor)" indicates a cured film having a crack.
[0211] (v) Insulation Reliability
[0212] On a flexible copper-clad laminate (the thickness of a
copper foil is 12 .mu.m, a polyimide film is Apical 25 NPI
manufactured by Kaneka Corporation, and the copper foil is bonded
by a polyimide adhesive agent), a comb-shaped pattern (line
width/space width=100 .mu.m/100 .mu.m) was formed. The flexible
copper-clad laminate was then immersed in a 10 volume % sulfuric
acid aqueous solution for 1 minute, washed with purified water, and
subjected to a surface treatment of the copper foil. After that, in
the same manner as in <Preparation of Coating Film on Polyimide
Film>, a cured film of a photosensitive resin composition was
formed on the comb-shaped pattern, so as to prepare a test piece.
The test piece was set in an environmental test apparatus at
85.degree. C. and 85% RH, and a direct current at 100 V was applied
to both ends of the test piece, so as to observe a change in
insulation resistance values, an occurrence of migration, and the
like. The evaluation was carried out based on definition as
follows:
(I) "G (Good)" indicates one in which 1000 hours after the start of
the test, a resistance value was not less than 10.sup.8, and no
occurrence of migration, formation of dendrites, or the like was
observed; (II) "P (Poor)" indicates one in which 1000 hours after
the start of the test, an occurrence of migration, formation of
dendrites, or the like was observed.
[0213] (vi) Wettability
[0214] Wettability of each of the cured films prepared in the
aforementioned item <Preparation of Coating Film on Polyimide
Film> was measured in accordance with JIS K6768.
[0215] (vii) Solder Heat Resistance
[0216] In the same manner as in the aforementioned item
<Preparation of Coating Film on Polyimide Film>, a
cured-film-laminated film was prepared by applying the
photosensitive resin composition on a surface of a polyimide film
(manufactured by Kaneka Corporation, APICAL 75NPI) having a
thickness of 75 .mu.m.
[0217] A resultant coated film was floated on a solder bath that
was completely melted at 260.degree. C., so that a surface of the
resultant coated film on which surface a cured film of the
photosensitive resin composition was formed made contact with the
solder bath. Ten seconds later, the coated film was pulled up. This
operation was repeated 3 times, and the adhesive strength of the
cured film was evaluated by a cross-cut tape method in accordance
with JIS K5400 as follows:
(I) "G (Good)" indicates a cured film in which no detachment was
observed in the cross-cut tape method; (II) "U (Unsatisfactory)"
indicates a cured film in which 95% or more of grids remained; and
(III) "P (Poor)" indicates a cured film in which the amount of
remaining grids was less than 80%.
[0218] (viii) Warpage
[0219] In the same manner as in the aforementioned item
<Preparation of Coating Film on Polyimide Film>, a
cured-film-laminated film was prepared by applying the
photosensitive resin composition on a surface of a polyimide film
(manufactured by Kaneka Corporation, APICAL 25NPI) having a
thickness of 25 .mu.m.
[0220] The cured film was cut out into a film having an area of 50
mm.times.50 mm, and the film was placed on a flat and smooth table
so that a coating film (cured film) thereof turned up. Then, how
much an end portion of the film was warped was measured. FIG. 1 is
a schematic view illustrating which portion in the film is to be
measured. As the amount of warpage on a surface of the polyimide
film is less, stress exerted on a surface on a printed wiring board
becomes small. This results in that the amount of warpage of the
printed wiring board is also decreased. In view of this, it is
preferable that the amount of warpage be not more than 5 mm.
TABLE-US-00004 TABLE 4 Evaluation Com. Com. Com. Com. Item Ex. 5
Ex. 6 Ex. 7 Ex. 8 Ex. 6 Ex. 7 Ex. 8 Ex. 9 Photo- G G G G P P G G
sensitivity Adhesive- G G G G G G G G ness Solvent G G G G G G G U
Resistance Flexibility G G G G G G P G Insulation G G G G G G G P
Reliability Wettability 38 38 38 36 38 38 38 30 or (mN/m) less
Solder Heat G G G G G G G G Resistance Warpage 0.0 0.5 0.0 0.0 2.0
0.5 20 mm 0.0 (mm) or more Abbreviation: Ex. stands for Example;
Com. Ex. stands for Comparative Example; G stands for Good; U
stands for Unsatisfactory; and P stands for Poor.
Comparative Examples 6 to 9
Preparation of Photosensitive Resin Composition
[0221] A synthetic resin, which was obtained in any one of
Comparative Synthesis Examples 1 to 4, a (B) thermosetting resin, a
(C) photosensitive resin, a (D) photopolymerization initiator, and
other components were mixed to prepare a photosensitive resin
composition. Respective amounts of constituent raw materials in
terms of a resin solid content, and types of the constituent raw
materials are shown in Table 5. In Table 5, the amount of
1,2-bis(2-methoxyethoxy)ethane as a solvent indicates a total
amount of solvent including a solvent contained in the synthetic
resin solution and the like. The mixed solution was set in a
defoaming device so that the solution was completely defoamed. A
resultant solution was evaluated in the same manner as Example 5.
Evaluation results are shown in Table 4.
TABLE-US-00005 TABLE 5 Unit: Part by Weight Com. Com. Com. Com.
Component Ex. 6 Ex. 7 Ex. 8 Ex. 9 (A) Resin C 60.0 -- -- -- Resin D
-- 60.0 -- -- Resin E -- -- 60.0 -- Resin F -- -- 60.0 (B)
N-665-EXP <1> 10.0 10.0 10.0 10.0 NC-3000H <2> -- -- --
-- OXT-121 <3> -- -- -- -- (C) A-9300 <4> 3.0 3.0 3.0
3.0 BPE-1300 <5> 12.0 12.0 12.0 12.0 (D) IRGACURE 819
<6> 2.0 2.0 2.0 2.0 Others Barium Sulfate 12.0 12.0 12.0 12.0
Aerosil R-974 <7> 1.0 1.0 1.0 1.0 1,2-bis(2-methoxyethoxy)-
50 50 50 50 ethane Solid Content Concentration 66.6 66.6 66.6 66.6
of Photosensitive Resin Composition Solution <1> Cresol
novolac type polyfunctional epoxy resin, trade name: EPICLON
N-665-EXP, manufactured by Dainippon Ink and Chemicals <2>
Biphenyl novolac type polyfunctional epoxy resin, trade name:
NC-3000H, manufactured by Nippon Kayaku Co., Ltd. <3> Oxetane
resin, trade name: Aron Oxetane OXT-121, manufactured by Toagosei
Co., Ltd. <4> Ethoxylated isocyanuric acid triacrylate, trade
name: NK ester A-9300, manufactured by Shin-Nakamura Chemical Co.,
Ltd. <5> Bisphenol A EO-denatured diacrylate, trade name: NK
ester BPE-1300, manufactured by Shin-Nakamura Chemical Co., Ltd.
<6> Product manufactured by CIBA specialty chemicals Inc.:
Photopolymerization initiator <7> Product manufactured by
Nippon AEROSIL Co., Ltd.: Silica particles
REFERENCE SIGNS LIST
[0222] 1 Polyimide Film Including Photosensitive Resin Composition
Thereon [0223] 2 Warpage Amount [0224] 3 Flat and Smooth Table
* * * * *